Kubs

I just replaced the points distributor with a Mallory Max Fire unit and ran new wires for ground, 12v power, and tach signal. I used the factory 12v source at the firewall bulkhead and replaced the resistance wire with a pink 12ga wire. I ran a wire to the ground strap from the motor mount to the block for ground. I also replaced the tach with an electric version so I had the dash pad out and pulled the steering column to do so.

I had the battery on charge all day so I knew it would be good. I hooked up the terminals and the car remains completely dead. No interior lights, nothing when I turn the key, nothing, Nada, zilch. I checked for 12v from the starter positive to the block and it was good. I checked from the positive battery terminal to metal under the dash and got 12v. So this tells me the body and block are grounded. This leads me to believe the issue is in the dash or steering column. I went to unbolt the column and then all of a sudden the interior lights came on. While they were on I went and checked my new connector at the distributor to verify I had 12v (it did) and then went back to try and start the car. I sat in the seat and all the lights went out again.

I'm going to go pull the steering column and check behind the dash, but I'll just be going blind looking for stuff. Any ideas what might have come loose putting the tach in place or removing the steering column that would kill power to the whole car?

mikem350

Sounds like the bulkhead connector (wire bundles) got unplugged at the firewall. I would unplug it and spray contacts with WD40.

Kubs

I did have this unplugged while running a new power wire. I will unplug it again and spray the contacts. Thanks for the idea!

I tried wiggling it to see if the interior lights came back on but they didn't. Perhaps just an unplug and reseat will fix the issue.

Kubs

So I cleaned all the large chassis grounds and still no luck. I removed the bulkhead connector again an inspected. I get 12v on the engine side of the connector but not on the interior side. The BAT terminal shows 0.02 volts instead of 12v so something is getting through. I guess my next step is to take the fuse panel apart and see what I find. Thoughts?

The13Bats

this happened on my 66 it was really filthy and jiggling did nothing,
Not saying it will fix your issue but on my 66 the plug was nasty cleaned it up and reconnected worked great.

SH-60B

Look at the ignition switch to be sure it'e completely plugged in and if so, check for 12 volts going into it.

Kubs

I'll try taking it apart again. What would you use to clean it?

It is plugged in, but haven't checked voltage to it yet.

I have thing to do with the wife's family today but hopefully I can get back out in the garage tonight. Keep the ideas coming!

Kubs

I spoke with DUB tonight. Since I have power at the engine side of the bulkhead, I ran a jumper wire from that terminal into the back of the fuse box where that terminal connects. I got power at the ignition switch and fuses, and all interior lights came on. I cleaned all the terminals and plugged the connector back in and got power again, until I turned the ignition key and then it all went dead. I'm gonna try taking the fuse box apart and see what I find.

The13Bats

Mine was extra nasty I used engine cleaner and then rinsed it then WD40 or whatever spray oil I had on hand,

69Vett

those 50 year old bulk head/FuseBlock connectors can rust and corrode on the inside,
take it apart and inspect, may have a connection corroded and broken off.
Take it apart inspect back of Fuse connections, its a pain to get to it.

Kubs

Yeah I ended up using brake parts cleaner and compressed air. I oiled it with an AMSOIL electrical connector protectant.

Yeah that will be my next step tomorrow. I'm not looking forward to it. I am a little surprised though. This car was stored indoors for 31 years before I bought it. Took very little to get it running and I drove it in the fall before parking it. It wasn't until I decided to install 12v ignition that the problems started...

69Vett

also the fuse clips themselves become corroded, and weak,
then they won't clamp the fuse tight enough, to make a good connection.
I had to swap out a harness due to bad fuse connections.

your symptom sounds like a bad body Gnd. to me.
also verify your Body/Birdcage to frame Gnd. connection is good.
on a 69 this small braided 3/8" line goes from body to frame, app. where the dimmer switch is located,
under the car, hard to find, and it just clips on the body.
I add a beefy body gnd. on the cars I restore.

easy test for body gnd. jumper cable from negative post to metal birdcage/body.
if all lights come on, you have identified the problem. good luck.

I am assuming you verified good interior harness gnd, located on the drivers side wall just left of the light switch,
Do not just look at it, scrape paint and use a electrical lock washer under the connection.

Kubs

I cleaned all grounds going from battery to frame, to engine block, and birdcage. I will try jumping from battery to birdcage just to verify, but when I test for 12v between the positive battery terminal and the ground on the driver pillar I do get 12v.

I find it very odd though that when I used a jumper wire from the bulkhead terminal to the back of the fuse box I get a constant 12v at ignition switch, fuse box, interior lights, etc without any problems. I can turn the key and move stuff around and the lights stay on. As soon as I plug the bulkhead into the fuse box it becomes intermittent again. I will remove the fuse box and look for anything loose inside, but I can't understand why it works with the jumper wire and not with the connector plugged in. Its very frustrating.

Kubs

So I got the fuse box apart. For starters the upper right hand screw was loose and I could rock the box back and forth a little. However, if the bulkhead connector is screwed in it shouldn't really effect the connection. The FEMALE terminal is maybe slightly compressed. It's possible it may not have been making a good connection. I don't know. I ordered some female replacement terminals and they should be here in a few days. In the meantime I am going to clean each individual wire/connector and hope it helps. I'm lost otherwise. I pulled on all the wires and nothing feels loose or looks corroded.

12v feed FEMALE terminal.


Back of bulkhead


Inside fuse box

69Vett

use needle nose pliers, crimp the back section on both sides, this will make a tight fit, and still allow you to slide into place. a couple of those fuse holders look blackened from heat, this creates oxide/corrosion making a high resistive connection, which induces more heat.
be sure to clean those really good wire brush dremel tool, or sandpaper worst case.
its best to read resistance thru wire, thru fuse holder, back to the wire on the other side.
this will test your fuse holders for power robbing resistance.

Kubs

Thanks for pointing that out. It was so uniform I thought it was some type of coating. It doesn't look "burnt" in person, but I will be sure to clean those and see what happens. Got any tips for removing the ends from the fuse box? Im sure just cleaning the exposed back of them won't help much.

Omarsvette

Might wanna check your fuseible link. There right by the distributor. If those have corrosion or burnt it will cut power. There is one on the horn relay also. Just wiggle/bend em n see what happens

69Vett

only bother to clean where there is physical contact, between fuse and/or connectors,
the dark tarnish is a good indicator of previous heat but does not affect resistance except where physical contact is made.
the units that riveted in, pretty much require cleaning inplace.
careful those old backlight black housing can crack and break, pretty easy.

Kubs

I took the night off from doing electrical last night and instead did something I knew I wouldn't have any issues doing. I got my sidepipes mounted and started re-installing the new chrome pieces that came back from getting re-dipped. I needed a feel good day!

Tonight I am going to start cleaning the contacts on all the terminals.

billschroeder5842

Perseverance; it is what owning a C3 teaches.