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-

Chasing the Hapy Electrical Gremlins (part 3)

Continuing on our journey through the darkness of the wiring rat's nest.

 

Shouldn't Have Cut That

not quite "before",
dashpod already pulled

I'll just jump right into the interesting part. Well, mostly. I started in the engine compartment and removed the wiring related to the coolant heater first: the relay box, the wires down to the glow plugs, etc. That much was great. Then, I moved on to looking at some of the wiring above, and as the bold-faced line implies, I cut something I would best not have.

 

Reflect back to the last time I clowned around on this wiring, I dug deep into the fuse-box. I started by pulling the fuses for circuits Hap doesn't need. Circuit by circuit, I cut that unnecessary wiring by referencing fuse sockets where the fuses had been pulled. That plan worked great. Lots of extra wiring got removed, and the engine still ran. I still had the sporadic not-limp-mode, and the occasional Hapy-don't-wanna-start issues, but they both seemed improved. Well, this time around, I got into the fusebox and saw a few wires that did not appear to have a partner on the other side of the fuse. So, I figured I just missed them the first time, and cut them. Well, that was wrong. Their "missing partner" was actually a common-line always-hot (circuit 30 in VW-speak) that was kind of hidden from view. Well, I didn't see them anyway. The wires I cut are for powering "engine control" circuits, of course. So, kinda important. Ugh.

Fuse Box Smaller

don't actually need
any of these relays

Once I realized that the wires I cut were critical, I needed a new plan. A while back, I bought a small relay box thing off eBay that has 6 relay slots and 6 fuse sockets. Once it arrived, I looked at how many fuses were in the donor fuse box and how many sockets were in that smaller box and the math did not add up. That was all before I did the clear out I mentioned above. After that, I was down to 7 fuses, and one of them was for the OBDII plug that I don't actually use. So, I think the fuse socket numbers may work. As for the relays, I only need 2 of the donor relays: the infamous 109 (main power) and old 180 (glow plugs). All the other ones can go, which leaves me 4 slots for other things, like the "RUN" and "START" trigger relays I have connecting the ignition from the front to the electrical from the donor. Neat. I didn't mean to change the fuse box and the relay plastic holder thing, but when I cut those two engine control wires the die was cast.

Label, Label, Cut

smarter way to remove
extra wiring

So, into the darkness we go. I started with the more obvious wires, like the thin little wires on the 180 (glow plug) relay. Then, I moved on to the T10 plugs. There are 5 (Blue, White, Black, Orange and Brown) 10-pin plugs in the mix of all that rat-nest. I unplugged them, and started dissecting by labeling either side of the cut, describing what is on the other side, and cutting. This picture on the right here explains the wire coming from the ignition switch position 86s as an example of how I dealt wit the wire-snarl.

While that sounds like quick work, I have moved slowly, researching each wire first, to make sure I don't have another "engine control" mishap. And, I want to do more than just label where it went; I want to know what it does first. This is a lot like a jigsaw puzzle where the more you do, the faster it goes until you eventually have all of the wires you intend to cut labelled and cut apart. I am almost done, which means the next post on wiring should include some building back up.

Diagramming

One last thing I have been doing, is crafting my own wiring diagram. I started by scanned the wiring diagram for the early ALH engine (80-pin ECU) from the Bentley. There are 13 pages. I am examining each circuit across the diagram and editing the image of the page to reflect what my circuitry will look like. I am retaining the original circuit numbering, etc. but adding the number of the fuse that I am using in the new fuse box to the documentation. Perhaps more importantly, I am erasing the wire references to things that I no longer have, like the coolant warming glow-plug stuff. My thinking is that this way someone who knows the original wiring (looking at you, Justin) can understand the diagram just as well as I do. This diagram will replace the diagrams in the 3-ring binder, since the 2 sets in there are both for later ALH models, so they are informative, but not exactly 100% representative. Between the cold and the dark, the diagramming effort helps me feel like I am moving forward while also creating clarity around the work.

My CoViD-19 Plea

I take a 2 mile walk pretty much every day to shake off the cabin fever and to get some exercise. Every day, I see 20-30 people also out taking walks, riding bikes or taking a run as well. That's great except I can count on one hand the number of people I encounter with a mask on at all (even worn wrong). The other day, I counted 3 people out of 28. Seriously. Our tiny state is consistently seeing over 1200 new cases a day, which is alarming when you consider our "summer peak" was 430 cases a day. Please keep your masks on, its not a political statement, it's not a chin-strap and it doesn't work unless it covers your nose and mouth. It's to protect others from you, not the other way around. We don't know if you have the virus or not, and quite frankly, if you're wandering around without a mask, and hanging around with others who don't have masks, then even if you had a test today... you don't know either. Just because you're outside doesn't mean you can run/walk/bike right past other people a-huffin and a-puffin (and sometimes a-coffin) without a mask. We are all tired of this, but that doesn't change anything about the importance of respecting it, and each other --