Hapy Electrical Fix and Planning

A few weeks ago, I rotated the headlight switch clockwise and that caused a short that allowed a wire to release it's smoke. Today's post covers that resolution, with some expected twists and closes with a plan to update the fuse box.

Poof

72 bus wiring diagram

First, I accept that what happened was entirely my fault. I turned a push-pull knob, and the housing was loose so I created a short. At first, I thought I had grounded a pin on the back of the switch. Based on the wire which fried, I'm not so sure, but the grey wire fell off of pin 58. That wire fall was what caused the running lights to not function: they tie into fuses 1 and 2 which control them. It wasn't wire 58 which fried.

So, I dug into the interweb. I found another person who had the buzzing noise from their flasher relay and they discovered the root cause was that the dashboard did not have power. Sounds about right, I suppose, so we remove the dash to see. The dash removes with 4 screws. If you are fortunate enough to have the vent and oily-smelling-air controls, you may need to manage them first. I have the older style controls which originally had the little colored spring-loaded clips. Of course, Hapy didn't have the colored clips, and still doesn't. Anyway, remove anything from the vent control levers which impede the dash removal, remove the 4 screws and detach the speedometer cable. Then, the dash lifts straight out (a little diagonal) to the steering wheel. At that point, I rotate it so the face points to the floor. To me, this puts the least pressure on the wires while exposing them for me to see. From here, I could see that the black wire from fuse 12 that delivers 12V to the dash had it's plastic casing melted off. How and why that wire fried rather than popping the fuse, I don't know. The fuse was and is still there, it was relatively new (like, in the last 5 years), the right rating and it was seated properly.

Clumsy

1 fried wire

Knowing which wire needed to be replaced is a great first step. Getting that wire replaced without negatively impacting anything else in the original electrical system, however, is a virtually impossible task. Such was the case this time. First, I pulled the wrong wire out of the fuse box, and as I did, I dislodged a couple of fuses. Then, I got the wire back in and dislodged some other ones. Finally, I found and removed the bad wire from the fuse box, bumping a wire out of the high-beam relay holder as I did. Neat.

I formed a new multi-female-spade-connector wire, using the fried one as a pattern. With a multi-meter, I confirmed the connectivity between all of the end points had 0 resistance and returned to Hapy's driver seat. I plugged the wire into the tabs on the dash, and dangled it behind, finding the tab in the fuse box. Again, I unsettled a few fuses, but once they were in place again, I started testing. First, I confirmed that the running lights and headlights came on. It being daytime, I could tell the lights were on, but not that the headlights were the high-beams. I turned the key to run and the buzzing was gone. The turn signals worked, the hazards worked, and continued to work when I turned off the key. I even test started the engine to prove things were good. What I didn't test: the wipers. It seems that when I was messing around with the fuses, I failed to reseat fuse 11 (which controls the wipers and the rear defogger) after reseating what felt like all of the others -or- another wire fell off. I didn't discover that the wipers didn't work until I tried to take a drive at night in the pouring rain. So much fun. I don't think Hapy likes the winter weather very much; he does seem quite persistent in staying in the driveway.

About Had It

So, after spending so much time diagnosing issues only to discover the issue was the 50+ year-old fuse box or really the style of fuse used in the 50+ year old fuse box, I have decided to look into replacing it. I say that because the wire that fried was on a fuse that didn't blow and the fuses are in the box so loosely now they become disconnected simply by brushing past them. Based on my research, I understand the fuse-box layout / purpose to be this table below. I will replace with a simple 12-slot 12-independent-circuit box that uses spade fuses instead of the old buss style. It will ultimately use the same circuit numbers as before for all of the things I am keeping (never had ambulance fans, nor ignition buzzer, nor interior lights). Plus, it will include things I need, like radiator fans and the fan for the heater.

Fuse #	Original Purpose	Changed Purpose
1a	front running lights, license plate light
2a	rear running lights
3b	passenger low headlight
4b	driver low headlight
5b	passenger high beam
6b	driver high beam
7*	open? looks like it was for ambulance fans	radiator fans
8*	emergency flasher and interior light	emergency flasher only
9*	ignition buzzer, rear interior light	interior heater fan
10#	horn, brake light warning switch/light
11#	windshield wiper, rear defogger	plus the windshield washer pump
12#	dashboard, emergency flasher
	rear backup light

a: supply-side from light switch

b: supply-side from headlight flasher (dimmer relay)

*: always hot

#: switched

&: inline fuse not in fuse box

I will be adding a master circuit-breaker as well back by the starter (where the main 12V source for the fuse box comes from) so there is a safety on the entire #30 circuit that goes to the ignition and the head light switch via the supply-side of the always-hot fuses. I do not know when I will get after this, though. The joy I have had since removing the rat's nest of wires for the engine control has been significant. The wires for the original bus have their problems, and I will be replacing some of the runs (particularly the rear tail lights), but for the most part, they have been up to the task. I just need to find a way to stay somewhat dry and maybe a little not-freezing so I can get after it. Since it is January, I recognize my opportunities for something this big will probably not appear for a while. Still, I can't keep letting smoke out of the wires, and I would very much like to get Hapy out of the driveway for a safe drive-around before spring. For the Pacific NorthWest, that starts with getting the wipers working again and then getting the high-beams turned off.

That's it for today. Thanks, as always, for following along-

Hapy Test Flights

After a fall/winter/spring of making modifications to Hapy, we took him for a test spin. Today's post covers that, the discoveries made and resolved and then another test drive.

The Changes

First, off, let's recap some of the changes since we last drove Hapy. Recall, that last run was a drive to Cornelius after resolving the stammer by cleaning up the vacuum lines and appliances. That was our last drive (except for the decibel tests) in those loaned-by-GratefulEd seats. We now have Sprinter seats. The old flooring was removed, CLD, jute insulation and MLV was laid in it's place. Of course, we have sound deadener all over and the stereo is operational (it was before, it's just better). On the mechanical side, the engine has a "cold" air intake now and there is a rear sway bar for handling. It is a different feel. More different, I think, is my familiarity with driving him. I have been driving GoRo (the Audi A4) and ToyoTruck, which are much more modern. So, my frame of reference is a little off and the Sprinter seats sit much higher, so I have to lean over to reach the stick now, especially when pulling away from a stop sign. I find myself hunched, and twisted to look left for oncoming traffic. Regardless, I think it will take a few drives to re-acclimate to driving the old bus. Looks like there will be more bus driving ahead. Sweet. One thing worth noting, I think: again, for the entire drive (albeit a short one), we didn't have the stereo on. Funny how much effort I put in and how little it gets used on the road. There is just something about riding in the bus that lends itself to no radio, and carrying on a conversation instead.

The Drive

On to the drive! Hapy started right up like he had been driven the day before. The throttle is super responsive, and the engine drove like a champ. He still doesn't like 2nd gear, but I haven't done anything to address that (it might be my install of the Scat short-throw shifter). The overall low-end drone is MUCH quieter, but some rattles remain, especially the screens in the jealous windows. I probably have them installed incorrectly (this video shows correct). Hapy still stops well, and he takes corners WAY better. There was almost no sway around street corners; of course, we did not drive very far nor very fast. We simply drove to a nearby park, played with the dog and returned home by way of the local c-store for some ice cream on a stick. The combo oil pressure / temp gauge still works great, and we did not throw any codes. While we didn't get above 35mph, the sound inside the bus never grew so loud that we couldn't talk at a conversational level. We could not hear the hum of the tires at all, and we really did not notice the sound of the engine. We could hear it, sure, but it was not as ever-present as it used to be. Recall, I used to describe the noise while driving the bus like sitting in an old metal shed next to a running a diesel generator, in a wind-storm. It is definitely not like that around town. I will execute a full decibel test lap to test the noise at highway speeds, but first, there are some things to fix.

The Issues

First, the exterior lights continue to produce phantoms. The brake pedal causes a bunch of the exterior lights (like the front running lights?) to light up, but not both brake lights. Also, the turn signal doesn't work when the brake pedal is pressed. No pedal and no running lights on... and the blinkers work. I remembered that I had the exact same experience when I took Hapy on that decibel test drive (buried in the Hapy Noises - Part 2 post). So, nothing I did over the winter caused it, but nothing fixed it either.

Probably equally important, the fan switch no longer triggered the fans to fire up. After we returned home, I found that one of my wiring bits had become disconnected. While repairing, I noticed how hot the wires would get during testing, and decided that I had gone too thin a gauge in some areas. So, I replaced the merged fan ground wires with individual 14ga grounds, and improved the supply-side to 14ga as well. The fans now both work, and the wires are air temperature.

The speedometer didn't work. I must have disconnected the speedo to get into the dash at some point over the winter that I don't remember and failed to reconnect it. This took no brainpower, just lots of patience opening up the dashboard, and trying not to upset any of the wiring back there.

We dropped into that awful 1200RPM limp mode right before we shoved off, but it only happened that one time. Believing I had fixed that before, this was especially frustrating. I must have bumped the wiring connection at the pedal while installing the jute and MLV. I checked those connections (pressing the joint-points firmly between my fingers), but nothing felt off. After multiple drives since, Hapy has not dropped into that 1200RPM limp mode again. 

Last, Hapy had not yet received his annual Spring cleaning (after-photo is at the top). So, he had a blanket of pollen on his pop top, moss on his window seals / windshield wipers, dull looking paint and dirty windows. The spring wash is the biggest of the year, taking a couple of hours, but it is so worth it.

Exterior Lighting Diagnosing

I have tried so many times to figure this out, and so many ways, but I had not been successful. I won't list them, but between resistance and voltage testing everywhere, running test wires the length of the bus, and replacing things, I thought I had tried everything. This weird brake light thing had been a recurring phantom for years, practically since I first did the engine swap. One of the frequent causes for the issue to return after being gone for a while was a remove/install of the battery. This always seemed strange. Sure, the battery is part of the electrical system, but why would it re-conjure an electrical ghost? It occurred to me this time around that the old 20-pin diagnosis plug is back by the battery. Perhaps my incomplete removal of that plug and related wires is a contributing factor?

Unable to determine this through my prior methods, I did something completely different. I removed the tail light assemblies from the bus, letting them loosely hang in the body holes. I took a different 12V auto battery, and ran a test wire from its ground post to the body ground point next to the main on-board battery. Using a fused wire, I touched various light circuits to see which ones worked as expected and which did not. All of this time, I had believed the issue was in the passenger tail-light: it is the light fixture closest to the battery, so I thought I was bumping something while installing the battery. Nope. The tail-light circuits would fire the correct lights. When I ran the same test on the passenger light fixture, lights were batty like I described above.

I checked the wiring diagram related to the driver tail light, and noticed that there was a tie-in between it and the battery location: the old test plug circuit. The yellow circled 9, 10 and 12 which tie into the driver tail light all correspond to the pin numbers in the plug. I knew that the running light was the one that was lighting up in-error, so I figured that red wire was the compromised one. I cut it off at the tail light, and the phantom behavior ended. Both brake lights illuminate when I step on the brake pedal, and all the running lights light up correctly (and only when I turn on the lights, not when I step on the brake).

 

I ultimately cut off all of the wires going into that old diagnosis plug at the plug, and cut the diagnosis wire from the passenger-side rear turn signal. I will probably have to go back into the driver side and cut off the remaining diagnosis wires to make sure I have really exorcised the electrical demons.

Victory Lap

With the brake lights working, the speedo showing speed, the fans firing and the body looking clean, Hapy and I were ready for a test. I figured that I had numbers for the test lap around the neighborhood from last Fall (documented here), so combining a test lap with a decibel collection made sense. Other than all of the changes I made for sound containment, there were no only other variables. Well... I took one lap, but it started just pouring rain, so I took another one. After that one, I realized that I did not know which "filter" to use on the reader because I didn't document that. I know I made a choice last time, though. Still, I think the test was valid enough for my not-terribly-scientific method. This time, I just used the default "A" filter. I did one last lap, but discovered at the end that I had failed to start the dB recording. Sigh...

Fall 2021 (pre-sound absorb) test:

Sitting at idle (900 RPM): 60dB

Around town (less than 40mph): 65dB +/- 5dB. 75dB peak

On the byways (above 40 but under 55): 65dB +/- 10dB

Spring 2022 (post-sound absorb) test:

Sitting at idle (900 RPM): between 55db and 60dB

Around town (less than 40mph):  60dB - 65dB. 70dB peak during highest-rev

On the byways (above 40 but under 55): 65dB - 70dB

Looking at those numbers, I am not impressed, nor do I expect you to be. That was a LOT of work for not much gain. I hit my original goal of dropping the overall sound and the peaks by 5dB, but after the initial drive-about experience, I was expecting more. Again, I need to remind myself that 5dB is actually a large span. Consider, 60dB is normal conversation and 70dB is a running vacuum cleaner. That is a huge difference for an increment of 10. Also, consider that in the link I used for sound level references, it includes "passenger car" at 70dB. So, if my drive around the smaller test loop only peaked (and even then only twice) at 70dB, then Hapy is quieter than a typical passenger car inside. Okay, maybe I'm feeling a little better about it. One last thing to consider.... if I used a different filter last time, then the numbers collected last time should have been much higher, or my efforts were a complete waste of time and money. Since the perceived noise is so much better, I am inclined to believe that I used filter A last time too, since that is the default. Here's an interesting link about filters.

 

At this point, Hapy is ready for summer, and it really could not have happened any later. While I intend to circle back on parts of this project, I do not expect to have to take Hapy off the road to do so. Yes, the furnace needs a re-do, the fridge cabinet is still in pieces, neither the headliner nor the carpet is in... he is still ready for camping. So, for the next few months, we are going to enjoy that, and I will be returning my attention to Zed. Last Summer ended with Zed still in primer. I would like to end this Summer with him painted, and ready for interior work over the Fall/Winter/Spring.

Well, that's it for today. Thanks, as always, for following along-

The 80-20 Rule

I'm sure you've heard the phrase 80/20. If not, its a theory that the last 20% of the project takes 80% of your time. No where is that more true than working on old cars. In one of my last posts about the MG, I detailed all of the various things I had done, and how close it was to road-worthiness. Since that fateful drive, I have spent many many hours trying to diagnose the small electrical issues that remain (See Ug-letrical). Today runs through some more of that fun.

Seeing Green

The MGB has 4 major circuits running through 4 fuses. The brown circuit is "always hot". It basically runs from the Alternator to the Battery, providing juice to the headlight switch and power to the hazard relay. Red is for the courtesy lights: side marker, running lights, and license plate. Purple runs the horns, the clock, cigarette lighter and "dome" light. There are 2 lesser circuits: blue-stripped between the headlights and the headlight switch and red-stripped for illuminating the gauges. Everything else is on the Green circuit. Seriously everything else: gauges, wipers, turn/hazard signals, even the reverse lights and radiator fans. So, when there is a break in the green circuit, lots of weird things start to happen. It was odd behavior in this circuit which drove me to replacing the fusebox last fall. On my recent test drive (See MGB - Test Start, Test Drive), most of the things on the green circuit didn't work: wipers, turn signals, tachometer.

Following my own advice, I started with the fuse, and demonstrated to myself that electricity was making it past the fuseblock to the next step in the wiring. Fiddling with the fuse and testing wires must have shaken something free, though, because after simply testing voltage and wiggling wires, the wiper motor started working. So did the cooling fans. So, I started to focus on the turn signals and hazard flashers, recognizing that wire shaking could just as easily cause those things to suddenly stop working too.

taken from MG experience posting

Hazard
The hazard switch is one of the more complicated bits in the MGB electrical system. I covered the early diagnosis of this circuit earlier (see MGB - Ug-lectrical). It has 6 pins coming out of the back, with 4 clustered at one end and 2 at the other. The 2 pins allow voltage through when the switch is in the hazards-are-not-on position. This permits the turn signals to work. The 4 pins clustered together map a brown circuit wire from the hazard relay (into pin #3) to light up the "hazard" light in the center of the dash (pin 4) as well as fire both left and right turn signals (pins 1 and 2).

The Interweb says these switches get crusty and need to be flipped up and down a bunch of times to get them to work again. I tried that, but it didn't work. So, I moved back to testing wires and electrical bits. I thought I'd proven that it was the brown wire which led to the relay, by routing a new wire around it, but I actually proved that the original brown wire wasn't seating. Once I pulled the wire off and onto the relay a few times, the hazards started working.... on just the driver side. I concluded that the switch was faulty. Be forewarned: the new made-in-China switches fail often, and can be short-lived. In fact, the replacement that I got from Moss appeared to have failed right out of the box. Neat.

I shot DeOxit into the plug in which the hazard switch is attached. I took a short stretch of wire and tested the plug, to prove that it was indeed the switch and not the plug. One at a time, I jumpered from pin-hole #3 to holes 1, 2 and 4. The jumpers worked, and I was able to get the dash light and one side and then the other to act properly. This confirmed my suspicions: bad hazard switches, even out of the box. I plugged the originally-on-the-car hazard back in, and tried the turn signals. Now, they worked. So, the DeOxit cleared whatever was wrong on that side, but the hazard part of the switch didn't work. To remedy, I bought a New Old Stock (NOS) part off of eBarf. While expensive at $45, having a hazard switch is a safety item I should not be driving without. Even with the new, proven functional hazard switch, the lights wouldn't flash. The hazard relay, though, made the tick-tick-ticking sound. Now, I've read that the original Lucas hazard flasher relays are a bit touchy. So, I dug around in my electrical stuff and found a bunch of relays from the TDI swap on the bus. One of them matched the pin pattern from my MGB - Ug-lectrical post. With a basic black (black for grounds in British cars) wire grounding pin #31, I connected the wire from the ignition relay and the wire heading for the hazard switch. Viola! We have hazards and directionals!

Stopped
Once I solved the hazards, I moved on to the brake lights. I'd solved these before (See MGB fuse box), but with the work on the pedals and master cylinders, they stopped working again. Knowing what worked last time, I went straight to the brake light switch on the pedal box. With it in-hand, and the ignition turned to run, I pressed the little nub on the end (that lightly rests on the brake pedal arm), and the brake lights lit up. Perfect. This is a basic adjustment issue. I turned the adjustment nut further up the switch. Then, I fit the switch through the side hole and threaded it into the pedal box. I think I got some paint into the threaded hole as the switch started to bind. I cleared the holes with a bolt and re-threaded the switch. I had to employ needle-nose pliers to fully set the switch, but now, when the pedal is depressed about a 1/2 inch, the brake lights fire. I set the adjustment nut down against the pedal box, and one more little nagging issue is solved.

That's it for today. I'm still working through other 80-20 issues and hope to have the MGB ready to put to bed until the rains stop (and my money replenishes) so I can drive it to get a top put on. While I wait for that, I have a radiator replacement I need to do on the bus and C will need a second pair of hands getting the 280ZX road-worthy. And then, there's that broken daily-driver I mentioned last time... its a true target-rich environment.

Thanks, as always, for following along.

MGB - Ug-lectrical

One of my least favorite things when it comes to working on cars is electrical issues. Unfortunately, most people feel that way so when an older car starts having electrical problems, that's when they start appearing on craigslist. Today, I will cover my efforts on the "green" circuit in the little British car as I try to figure out why the turn signals don't work. First, for my US friends, happy Thanks Giving.

But I Thought...
Just about every electrical realization starts the same way. You're cruising along, doing your thing when some system just stops working. That sinking feeling is universal. As much as you want to direct your mind to a simple and easy explanation, it's not that easy. 'it could just be a really old fuse went bad". Yeah, sure. That's happened. I'm sure we've all read of an account on the internet when it was just a single fuse that went bad for no reason. I've never had that kind of luck. When a fuse pops, it pops for a reason. Regardless, that is the first place to go: check to see if any fuses are bad. Today could be your lucky day.

Wiring Diagramming

Once you've ruled out the fuse just popping for no reason, you need to start thinking about a viable reason for it popping. If it isn't a fuse, your problem is the same: rooting out what stopped working and why. This starts with a wiring diagram. With the advent of the interweb, lots of full color diagrams are available for free (or a small fee). Older cars have much less complicated diagrams, yet they have more problems because of age. I was able to find a nice electronic version of the MGB diagram at advance auto wire.

Diagram Analysis
This could be kind of fun, at least for a simple diagram like this one. When I look at the pages and pages of diagrams for my 2000 Jetta, its really not nearly as much fun. BUT, the modern diagrams are sub-divided well once you get the hang of it. Either way, find the sub-system that isn't working. On the single diagram, it might seem easier, but the many pages style have a table of contents. You just need to know the name of the system you're looking for. "Electrical thingy" won't be specific enough. Anyway, once you find the sub-system on the diagram, study the colored lines, and figure out where they connect with other things. In my case, I can see many components riding on the green wires. Some of them work and some of them don't. Since the turn signals leverage lots of the hazard wiring, I checked the hazards and they didn't work. So, I was able to isolate the areas of the green circuit which are the most likely sources of my troubles: the ignition relay, the wire from the ignition relay to the hazard relay, the hazard switch, the wire from the hazard relay to the hazard switch, the wires from the switch to the lights and the turn signal stalk/switch.

On-car Analysis

Equipped with this, I started looking at the most likely issue: the hazard switch. These are old and crusty, and they fail. The hazard switch pushes out from behind and a multi-wire plug can be removed to enable testing and replacing the switch. With my multi-meter, I checked continuity on the various posts (continuity test position is the icon with an arrow pointing right into a vertical line down near the bottom). I found that the switch would not send a signal to the right-turn post, so the switch was bad, but it should be sending signal to the left side. The switch is part of the problem, but not all of it. I moved on to the relay. I know the car can run, so the relay should be fine. To rule it out, though, I put the negative battery cable onto the negative post and verified that there was 12V at the relay post which powered the hazard circuit. There was, so this leaves the wire from the relay to the flasher, the flasher or the wire from the flasher to the hazard switch. I disconnected the battery again, ran a long tester-wire from the relay to the flasher, reconnected the battery and tried the hazard switch. The left side blinkers started flashing. Cool... except that meant that the issue was the wire from the relay in the engine compartment to the flasher behind the glove box.

Tearing into It

the 3-pin relay. 31 goes to ground

I figured the wire had a kink or was broken. To remedy, a new wire would need to be put in. Rather than have a lone wire routing back, I chose instead to open up the harness and identify the wire failure first. I couldn't find it. I did discover, however, that the previous owner had put an in-line fuse between the ignition relay and the flasher. I verified that there was continuity from the relay to the far side of the fuse, and again confirmed that the wire was not conducting. So, I removed the wire harness wrap. Inexplicably, the wire started working and the blinkers on the left side would flash when I flipped the hazard switch. Relieved that I wasn't going to have to route new wire, I decided to show Boo.

Unfortunately, the hazard switch chose that time to completely fail, so we could hear the blink-blink-blink from the flasher, but no lights. GAHH!! I love electrical issues. I swapped out the hazard switch, but the new switch had no effect. I checked the voltage on either side of the relay, and it shows 12V all the time now. So, maybe its a bad harness plug that the hazard switch goes into. More multi-meter time needed. Times like these, I ask myself how much work would it be to install an entirely new harness? The answer according to the interweb is 40 hours and $550 for the harness (See AdvanceAutoWire). Eek. Maybe I'll just keep playing whack-a-gremlin.

Relay and Pins
In case you discover your issue is the hazard relay, here's some useful discovery I had while investigating possible causes with the relay: The original 2-pin relays are still available, but 3-pin versions are more so. The 3rd pin (31) goes to ground, which, with old cars where the grounds can get dicey, that's a really good thing. Also, the 3-pin variety are very widespread and used as relays for all kinds of cars, bringing their cost down below $5 each. The original 2-pin relays are around $15. For some, that originality is worth the difference. I just want my flashers to work. Having a relay that is available everywhere is a bonus.

Unfortunately, this is as far as I've gotten on these electrical issues. Lots of cross-wind with the 280ZX, a daily-driver suddenly out of operation, and then there's the usual holiday crazy. Last, work is increasing in intensity as we approach "year end" and managers everywhere are realizing that bonuses are tied to delivered work that hasn't materialized yet. That usually means more pressure from above to get more done which leads to working more hours in the evening or on weekends. Looking forward to January and the return to a measured pace.

As always, thanks for following along...