Finishing the under-dash wiring

Posted on by November 7, 2021

I had a about half a day to work on this so my goal was to get as far as I could under the dash. It actually went very well. First I checked out the wiring on the ignition switch that worried me yesterday. Sure enough they were backwards, but as it turns out it does not matter. The switch is set up so you can’t wire it wrong. Nice. Moving on…

First I hooked up the headlight switch. This wiring had been modified on the original harness and my notes were wrong so I had to do some detective work. It was complicated because I can’t figure out how to take this switch out of the car. While I was doing this I also re=installed the instrument lamp dimmer and hooked up the power wire to it.
Next I put the spotlight switch together. Besides the left wire that I made yesterday I also made a temporary extension for the wire going to the spotlight. This wire barely reached the switch before. Eventually I will remove the spotlight and replace the wire but for now this will give me more room to work with. I installed the switch and attached the power lead to the fuse in the fuse block on switched power
Next I put in the switches for the Climatizer (heater) fan and defroster fan. The long lead is one I made earlier to reach the non-stock location of these switches. It ties to switched power on the fuse block. The short jumper lead feeds the power from the Climatizer switch to the defroster switch.
I changed the orientation of the switches from where they used to be. The Climatizer switch has writing on the knob and I wanted that text to be upright when the switch is off. The catch is that now the heads of the screws for the switch terminals are hard to get to. To get around that I had to remove the switches again, connect the wires, and re-install the switches. The left-most wire is the wire for the defroster motor. That wire is not great and needs replaced but to do that I have to remove and disassemble the defroster motor. That will be a job for another day.
Finally I installed the switch knobs and the lighter. I was about to make a new power lead for the lighter and realized that I had no intention of actually using it so I just left it disconnected. If I ever take up smoking I can hook it up.
Turn signal time! Here is the new turn signal switch. That dinky hose clamp is the first problem.
I want the turn signal switch as close as possible to the steering wheel. To do that the best place to mount it is on the housing on the steering column that the shifter is mounted in. So I need a bigger clamp. This is the one from the old switch. I thought about reusing it but it is too wide.
This is the biggest clamp I have. I think it is for a dryer vent. I test-fit it then cut it to length.
Oh yeah, that will work. I will just have to tweak the position a little
Nice!
I wanted the wiring for the turn signal up out of the way but I also needed to make sure I could connect the power and ground wires. This is what I settled on. The power lead with the fuse holder is getting power off the ignition switch. I looped the turn signal harness over the steering column and tied it to the main chassis harness with a not-period-correct zip tie. That ensures the connectors don’t have any strain on them. This would not work if I had a radio but I don’t so might was well use the space.
I found a threaded hole in the bottom of the dash where the factory heater controls are supposed to mount. I found a slotted screw that fit and used it to ground the turn signal switch.
Last task under the dash is the instrument lights. The new harness comes with the two sockets that plug into the back of the gauge cluster but there is a third custom light socket that lights up the ignition switch (of all things). Here is what that looks like. The can on the right screws to the dash above the ignition switch and there is a slot in it to cast light on the switch.
The harness comes with a kit to rebuild the custom light socket. I will have to put the parts on the wire and solder that little brass button onto the wire. I decided to reuse the spring from the old harness, it looked better made than the new one.
New harness ready to install. This was easy to put in, the biggest problem was getting the screw in to mount the ignition switch light. It is is tiny and has to be installed blind.
Done under the dash! Mostly looks pretty good. I will remove the tags when everything works. The old wire dangling by the flasher is the dome light wire. That has never been hooked up on this car. If I ever replace the headliner I can replace that then. I can clean that stuff up later.
I was about out of time but got as far as disconnecting the voltage regulator. These wires are scary bad! I am maybe 2/3 of the way done getting the old harness out but most of the rest is under the hood. That will have to wait though. I have other chores for the rest of today.

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