Did I say I like electrical, shoot me.

Electrical Systems Check

July 16, 2016

For the last few months I have been waiting for my body guy to be available to do some touch-ups. While I wait I have started checking the electrical system, right from plugging the battery in nothing went right.

Hooked the battery up and the brake lights come on, disconnect battery, adjust switch, hookup, test, good.
Turn on headlights, nothing. No headlights, no dash lights, no park lights, no taillights.
Pulled the fuse and the switch, checked continuity on all the runs and they were fine, checked for shorts as well.
Meter to the NOS switch, bad. not one position worked, dug out the original, bad. No amount of cycling would get them to work.
Made a jumper and plugged it in, checked each circuit at the switch connector, all good.
NOS Hazard, bad. Made a 4-point jumper, all good, blink, blink, blink.
Original Dimmer/Dome light switch, good, plug switch in, clip ground wire to the switch frame (switch panel is out of the car), test, good. In 69 the door switches were unplugged on the CHP cars, tested, good.
Rear defroster, NOS switch tested bad, cycled a few times, good. Plugged in, tested, good.

Now this is where it starts getting crazy(er).
On to the horn, battery on, push ring, nothing. Pull the relay hook it up to a power supply, nothing. Pull the relay from the Other Polara, test first, good, install, still nothing. Pull the horns, test on power supply, one good one bad. Pull both horns from the Other Polara, tested (just to be sure). Power to relay, check, check continuity to horns from the relay, good. Hooked horns up, used a jumper at the relay and horns blasted.

So we have a grounding issue on the horn circuit. First check column to ground, good. Original horn switch, good. No continuity from horn switch wire, unplug the column, good to the switch, not to the relay. Now the connection from the connector to the relay is a single wire with no splices or other connections. Oh wait, there is a modification done by CHP, they cut the wire to add switch to use the horn ring to run the siren. Ok, cycle switch to siren, nothing in either position. Check wires to switch, nothing? Great maybe I didn't follow the CHP wiring diagram right.

Time to get back to the factory and confirm that it works. A jumper was placed across the CHP cut and the horn tested, works.

Switch tested ok, check wiring to CHP diagram, good, check theory/operation it should work. Arrg!

Now I'm at loss? Recheck the checked known good stuff and now no ground from the column connector to the horn switch.

No keep in mind I have been under the dash a lot and often grab the wheel to get up, so I hook my meter up to the horn switch lead and to the wire at the other end and then turn the wheel, spotty. Then it occurred to me that I haven't actually locked the wheel down, so torqued it down to spec but still not perfect, put a socket ot it and hit it a few times with a soft blow hammer, problem solved. Checked horn, works, switch to siren, works (to relay, siren not installed yet).

Holly cow, about a week plus trying to figure all this out and I'm not done yet.

I'm still looking at options for switches and may take them from the Other Polara but it doesn't have the correct wiper switch so I took one I had the was a mess to see what is involved in cleaning/fixing one. While I was at it I mapped out the switch and made a list of connection for the two speeds and the off position.

Knowing to hookup I used a couple jumpers and a ground wire to test the wiper motor and for once it works as it should, moved to jumpers to the other speed and then park. I also had a cable tie on the wiper post to confirm rotation and park (a friend had the arm 180 out at the motor and the wiper arms try to go down before up)

With the wiper tested the motor was locked down and the crank arm tightened.

This weekend I plan to get my engine builder over (engine doesn't start without him here till he says so), we have run it several times but not through the key or the alternator, voltage regulator... basically none of the charging system. But till then I need to check the rest of the CHP wiring.

A few days later

My friend comes by and we meter out everything under the hood to confirm it is good before we try to fire up the car for the first time with the key, till now it was just hotwired.

After a couple false starts we tried and it just died, didn't take long to realize there was no gas in the tank, we had been running off a jug at the back of the stub frame. When I put the tank in I put the gallon or so of gas I had in the tank, we must have run through that. A quick break and back at it with 5 gallons in the tank, notice gas gauge works, 1/4 tank!

Fire it up and run it, check charging, do some tweaking, check temp, wait, no temp, no gas. After we ran it for a little while more we shut it down and start looking into the fuel gauge figuring it died. After some checking in the rear and at the kick we concluded it was probably a bad fuel gauge.

My friend leaves and I proceed to pull the cluster. I swap the gauge with another I had and put the cluster back in and hook the battery back up. As soon as I turn the key on I get sparks from under the dash, I turn the key off and disconnect the battery. A quick look inside and see no sign of fire I step away and take a break. Flashlight in hand i start looking through the switch panel and radio openings and see nothing obvious, stick my head up from the bottom, nothing.

So i pull the cluster figuring I'd have a better look with it out, soon as I pulled it out enough to disconnect the wires I saw the problem...

After looking over the wiring diagrams I speculate I had a dead short in the 2nd fuel gauge. I have several more boards and a couple more gauges so I should be good to go. I did inspect the harness under the dash and didn't see any problems. The plan is to replace the gauge and board and try again.