Electrical issues

[edison1970]

I think I have an idea on the direction I need to take but I thought I would get your feedback to see if someone who is better with electrical has a remedy.  I took my Cuda for a short blast two weeks ago. After a bunch of tire smoke in first and second gear, I  notice the oil pressure gauge dropping down to zero. I pulled over and the motor is running like a top. No noise and I look and the gauge is returning back up to the normal 3/4 mark. Get back to the house and it starts dropping but this time I notice the fuel gauge is doing the same. So I check all connections to the gauge cluster. All are tight. I start it again and all are working. I turn on the parking lights and they stop working. Turn on the headlights and the car dies. My thoughts are voltage regulator or alternator.  I checked voltage at the battery and jumps from 18 to 12 to nothing when running.  Is there something I'm missing or should I start with the Chinese voltage regulator?

[dodj]

Check the bulkhead connector first. Then ammeter connections.
Sounds like you have a connection corroded and or overheating. The more load...the worse it will get.

[ledphoot]

^^^agreed

When I removed my bulkhead connectors there was evidence of overheating, melting, corrosion etc. mostly around headlight and ammeter connections. The electrical design of these cars can use some improvements.

[edison1970]

I didn't run the positive wire the factory way. Ran a solid wire through the firewall eliminating the chance of a poor connection.  All wires are tight and clean. I checked the ammeter wires. Like new. Nothing hot or warm to the touch. I will pull and check connections at the firewall  next.

[Bullitt-]

  I could see a poor chassis ground causing any one of these issues.. There should be a ground directly from the battery to the radiator support & it wouldn't hurt to have a ground wire from the engine block to the firewall like used in later models for insurance 

[dodj]

Bullit's suggestion is good and along the same lines..make sure your VR is solidly grounded.

[Cudajason]

I recently had a similar with an overcharging issues.

https://forum.e-bodies.org/electrical-and-audio/11/-over-charging-issues-battery-issue-update/22970/msg277826#msg277826

I had a broken wire at the voltage regulator, always look for the simple solution first.

Jason

[Rich G.]

Weather it's charging or not shouldn't shut the engine off or turn the lights off unless the battery is dead. But if it was it wouldn't start right back up. Sure sounds like a ground or connection issue.

[edison1970]

Good info guys. I'm going to check the grounds as suggested.  Checking the wires to the voltage regulator was on my list.

[ledphoot]

If you start popping connectors off the bulkhead to look at 'em be careful not to break the retainer clips.... Pretty easy to do on originals and even possible to do on brand new ones, ask me how I know.. 

Luckily you can buy the connectors and it's easy enough to pop the contacts out and put them in to a new connector. But still a pain in the arse.

[edison1970]

 Thanks for all the feed back. It looks like I got it fixed. I checked and cleaned the ground to the radiator support.  Looked fine but I polished it up and tested the wire. Next I tested the wires to the voltage regulator.  All good. Finally I went to the bulkhead connector.  I pushed on one of the connectors and heard a "click". That was the problem.  Started the car and all gauges work and headlights came on bright and engine runs great.  I'm still going to run a ground strap from the engine to the fire wall and replace my battery cables. Again,  thanks for all the replies.

[dodj]

 

[Filthy Filbert]

Reminds me of when I was chasing a no-charge condition.  Ensured a good ground at voltage regulator.  no change.   Replaced the voltage regulator. no change. Tested alternator, part store said it was bad.  Replaced it.  No change.  Checked all the bulkhead connectors. no change.

lots and lots of head scratching. 

Then randomly, my hand bumped the tiny 6" long 12 ga wire going from the core support to the battery, and the wire came out of the crimped connector.    I thought "huh, that's odd"   replaced the crimped connector, and suddenly had full charge.   

The big negative cable going from engine block to battery was enough to ground the system to start and run the engine, operate the head lights, gauges, etc.   But not good enough for the voltage regulator to function.

[dodj]

Probably why they started adding that ground strap from pass side cyl head to firewall. Can't have too many ground wires with old cars..