Keeping it Cool

I wanted to post a quick update on the cooling fan work I did last night.  As you may remember from an earlier post, I was concerned about whether the fans kicked on during my anti-NASCAR test drives.  I watched the temperature rise on the UltraGauge, and even level off at 185*.  I think that was when the thermostat opened and the full coolant circuit (routing through the radiator) was active.  This allowed the 68* coolant that was sitting in the radiator to mingle with the 185* coolant leaving the engine.  Predictably, the temperature dropped temporarily and then increased again.  I didn't have the patience to watch the coolant rise too far above 190* before I got uneasy and stopped the test drive.  I should have hopped out at that point to see if either of the fans were spinning.  Wanting a backup system for fan activation was the driver for last night's efforts.

Relay Enabled
I re-attacked the fan wiring last night.  My first change was to tie the fans together so they both turn on and shut off together.  Having just one spin seemed silly.  To protect wiring, I have both fans activated off of an automotive (30A) relay triggered from the temperature switch in the radiator.  Now, when the "low speed" temperature is reached, both fans will fire.  I don't have a destination for the "high speed" signal yet, but I think I might wire it to my oil idiot light on the original dash.  That way, if I'm getting too hot, I'll have a visual queue to cool it.

Panic Switch
Now that both fans turn when the temperature switch says to fire, my concerns about whether that switch will always work kick in.  Honestly, I'm not sure if the current switch works.  Now, I could remove the switch (effectively draining the entire cooling system) and install a new one.  Yes, that would be the proper course.  Rather than do that, I wired in a panic switch for the fans.  Now, if I see the temperature running high, and lack the confidence in the fans turning on automagically, I can flip a switch (with an LED to show me that I did so) and fire them up.  The B+ side of the switch is running on circuit 30, so I can fire the fans after shutting off the engine.  Since the coolant will stop moving at that point, it is limited in utility, but it might help cool a little bit.  The tests of the switch and relay were positive, so I'm ready to test-drive again.

With all of these modifications, the wiring near the driver's feet has become, uh... rat-nest-like.  I'll spend some time cleaning that up tomorrow night, freeing up Saturday for test drives and final bits and pieces on the pop top.  Thanks for following along, and if all goes well, I'll be on the road Saturday doing more than just an anti-NASCAR this time.  WooHoo!