[RocktimusPryme]

I’m really close to just shredding all the wiring in this thing and putting in a 14 circuit universal.

This is my last ditch effort. Car runs, alternator charges. All the fuses are good. All of the fuses have power to them.

Headlights all work but are brighter on the right. I suspect that is grounding.

Tail lights I have got nothing. I have intermittent power to the blue wire (which supplies tail light power) but no brake lights no turn signals.

Brake switch has power and Is functioning.

Turn signal switch was broken. Got a new one but that didn’t fix anything. Somewhere under that dash I don’t have power that I should. The power loss is upstream of the single harness bundle that runs the length of the car. I checked it near the front door.

So the tail lights are intermittent with a brake somewhere and the others are MIA all together. Nothing is obvious but it’s an Italian food nightmare near the fuse box.

I made sure the grounds were solid at the tail light buckets. I had power to the passenger tail. Figured out why the right one didn’t. Went to the parts store for something and when I got back I had no power to the right one again.

Any ideas before I spend money on a universal kit? What is supposed to supply power to the brake and turn signals? When I found that bad turn signal switch I really thought that was going to be it.

[Bill Hanlon]

Power to the turn signal switch comes from the flasher in the wiring diagram you attached. Looks like the flasher is mounted on the fuse block, but I can't tell from the drawing which fuse supplies the flasher.

The brake light switch appears to get its power from either the same fuse or the one next to it. I can't tell which from the drawing you supplied. I've marked the two wires F and B in red on this portion of your drawing.

[RocktimusPryme]

I did put in a known hood flasher to check but that was before I made some other discoveries like the bad turn signal switch. I can try again and see what happens.

[Stuart]

I've had intermittent taillight issues where the contacts in the bulb socket were clean but had lost their 'springiness' so they didn't make continuous contact against the bulb terminals. You may have to splice in new sockets.

It seems like 90% of all automotive electrical issues are due to poor ground connections. For troubleshooting it can be useful to make a jumper wire going directly from the shell of a bulb socket directly to the battery negative terminal.

For reference, there's an online version of your wiring diagram here: http://www.oldcarmanualproject.com/t...re5765-335.jpg

[johnta1]

I think the wire supplying power to the rear light blue is pink?

Have you checked the Hi-beam switch on floor?
It's usually a cause of many problems.

Here's the schematic for 1962 Cat:

[johnta1]

My schematic is the one Stuart linked to.
(tree'd)

[RocktimusPryme]

Forgot to mention that I also noticed that one side of the fuse box isn’t getting as much voltage as the other.

So the left bank of fuses was getting close to 12v with the key on but not running. The right bank (the one with the flasher) was only getting like 8.5v. Is that normal or would that likely be a weak ground?

Also there is a section in the fuse block shaped like a cross with a bunch of male spade terminals. I have tested that with the headlights on and several of those are powered. But now they are dead. I suspect that is related to my intermittent tail light power. So I almost think it is something behind the fuse block.

I did pull it off the firewall to look at. Nothing dramatic jumped out. I saw in an older thread something about a contact cleaner for hobby trains. I’m going to grab a bottle of that.

I did pull off the plug at the foot switch and clean it. It’s functioning.

FWIW the bolb sockets could be bad, but at this point I don't have power way upstream of that. So I have greater problems at the moment. On the safari the tai light bundle runs down the passenger side. I stripped a little shielding from the wires at the front passenger door. Ive had power to the Lt Blue tail light wire, now I don't. Not sure why. Ive never had power to the pink/purple turn signal wires in that bundle.

[johnta1]

Probably a bad connection? Rust/corrosion? Could be a wire partially broken internally?

I saw a pic of the rear setup and the pink wire is the left turn signal and purple is the right. Lt. blue is the tail light.

Headlight I think is a straight run from headlights to dimmer and instrument panel, I think.

How many taillights are on each side? Takes a different flasher depending on how many lights.

[johnta1]

This pic is from the Service Manual:
(not sure how good it'll look on PY)


Looks blurry I guess.

[johnta1]

Try this:

1962 Wiring

[RocktimusPryme]

There was one connector on the back of the block that was fairly corroded. I have it earmarked for the hobby train drop stuff I mentioned. My parts car the fuse block and under dash wiring is immaculate, but Im leery of yanking it because I don't want to end up with two cars that have spaghetti wiring. That car is decent on its own, so I don't want to hack it up. Its good enough that someone will want it.

[Bill Hanlon]

The first thing you need to fix is the 8.5 volts on the fuse block with the flasher. John's diagram shows it getting power from a yellow/black wire connected to the ignition switch.

[RocktimusPryme]

Originally Posted by Bill Hanlon

The first thing you need to fix is the 8.5 volts on the fuse block with the flasher. John's diagram shows it getting power from a yellow/black wire connected to the ignition switch.

Yeah, that's what I was thinking my plan of attack would be too. I cant remember now which of the wires on the back was the one that had the pretty bad corrosion. Maybe its that one. I will mess with that when I get home.

I work in engineering so I am generally pretty good with schematics, but this was kicking my butt. Mostly because I found two or three problems that I thought were going to fix everything and it kept not working. It was demoralizing. Just talking through this with you guys is pumping me back up with confidence that I can get this to work without ripping it all out. Its a bit therapeutic to talk it out with other car guys who have fought 12v gremlins before.

I am confident the issue is under the dash, because again, while the grounds at the back to the light housings might be bad, I flat out don't have power to that bundle right now. I might start zip tieing bundles together just to make it easier to see what Im looking at under there.


Side note: There is a light green wire, with a spade on it hanging down near the fuse block that is hot. The spade is new, but Im fairly certain the wire is factory with a newer end on it. That wire infuriates me, because I cant for the life of me figure out what it is supposed to go to.

[johnta1]

With the pic in my link, it has a list of wire colors and where they go or are for.
Light green could be for the Hi-Beam Headlight indicator for one.

[RocktimusPryme]

Originally Posted by johnta1

With the pic in my link, it has a list of wire colors and where they go or are for.
Light green could be for the Hi-Beam Headlight indicator for one.

Yeah I was sitting here looking at that.

I was looking for a place it was supposed to go near the fuse block because there is where it is currently swinging, but I bet it has the length to reach up to the gauge cluster. So maybe its supposed to go up there and I was looking in the compete wrong place.

[RocktimusPryme]

I had some victories today. I’m honestly not 100% what fixed what. I made a better ground system. Between the body/chassis/engine. Then I removed the fuse box and did some work with a Dremel to clean some connections. I also cleaned the headlight grounds.

I now have turn signals at all four corners and the dash. I have brake light and all 4 headlights plus the dimmer switch work.

I still do not have tail lights. That blue wire is hot at the fuse block but somewhere in between there and the rear light harness it’s dead. I also didn’t figure out what that green wire goes too……I hate that wire.

[johnta1]

I'd follow the wiring from the dash toward the back and see where it loses power?
There probably is a connection around the seat mount area possibly>
(not sure where they are on an old car like that)


Celebrate the victories when you get them.

[RocktimusPryme]

I think the break is really close to the fuse block. There is a connection that doesn’t seem like it has power at a plug but it’s hard to get the test light in there.

I had my head all the way up under the dash I there are a bunch of wires that have some old electrical tape. Which is not in the good zone…….. I’m going to pull the tape off of one and see if they were all cut or why. They have tape on them.

[Bill Hanlon]

What fixed the 8.5 volts to half the fuse box problem? I hate it when a problem solves itself.

[RocktimusPryme]

Originally Posted by Bill Hanlon

What fixed the 8.5 volts to half the fuse box problem? I hate it when a problem solves itself.

I do believe that was me cleaning the contacts on the back of the fuse box. The side that was weak had the hot ignition wire down on the bottom supplying power and it was corroded pretty good. It could have been me cleaning up the ground system in the engine bay, but that feels like the fuse block.