Intermittent Turn Signals and Dim Dash Lights

[jimkov]

Hello, just drove my 71 Challenger to work this morning and after driving about a mile my turn signals stopped working and my dash lights went out. They did come on with a slow and weak blink twice but then died again. Could this be a bad ground? Were would the turn sognal and dah ground be? Headlights are working normal, HI beams too. Before the winter I changed the alternator, got a new Odyssey batter, added an OEM vintage regulator, and connected both ammeter wires to the same post. After doing these changes the car ran normal for a couple months. The dash lights have flickered at low RPM in the past but have never been unreadable or off during normal driving. The car has an edelbrock serpentine set for the 383 but the tension seemed good when I checked it thus morning. Thank you for the help.

 

[70pumpkin]

I have a similar issue on my 70 but haven't had time to dig into it. The turn signals work but the dash lights don't. Headlights and everything else is fine too.

 

[Ronbo73]

I would check the factory service manual for wiring. Check all of the grounds to make sure there is no oxidation/rust between the connectors and the chassis. Use dielectric grease to keep the ground connections from oxidizing.

 

[EW1BH27]

I had an issue with a $20 “new” alternator bought at Carlisle. Slow turn signals, dash lights went out at idle speed. Never thinking it could be the new alternator, I cleaned a ton of electrical connections & resorted to increasing idle speed and still the same. Frustrated I put the old original alternator back in and everything’s been good since.

Not saying it’s your problem, just passing on an experience I had.

BTW, when I asked the vendor why he was selling an alternator with next to no miles on it, he said, “I decided to go in a different direction”. Oh well, buyer beware.

 

[Challenger RTA]

As far as the dash light ground,it is grounded through the light bar and the frame of the dash. Also check the chassis ground in front of the battery. And of course the terminals.
Info here: Dash lights a Brighter possibility
Other then the possibility of fuses and switched power could be a problem.

 

[Challenger RTA]

alternator

This is so over looked. When the alternator is being checked are changed out. The ground is 50% of the issue if not 100%. I found this out decades ago. Changed Alts a number of different times.
One time changed alt on my daily commuter that has to go a 100mi+ a day one way. I can not break down I have to be there. Taking a bridge or road out and putting back that day or getting a power plant back up and running. Something to that effect.
The car I was driving the alt light would come on about an hour of driving. So I took the Alt off an other car I knew it was good. It was my backup work car. After changing it it seemed ok for a week or so but it came back on. This problem haunted me for about a year. Always had my 3rd eye on the alt light.
So I removed the engine wiring harness. This is a little more involved then an Ebody a few more wires. Inspected and cleaned all connections, fuse box and inspected for broken wires. Check computer ECM connections. ( Side note. If you didn't know the ECM controls the charging of the battery and spark in most cases if not all any more. Don't take this as gospel.) The ECM has to have a good ground also!
OK now I get back to the rest of the situation. Real short. It's the alternator mount the bolts and the holes need to be cleaned. Do you get that I'll repeat it. The mount the bolts and the mounting holes. That fixed my Problem. Understand that there can be other problems the bulkhead connector,wires and others. First you have to have good power supply for anything to work correctly.

 

[Challenger RTA]

Hello, just drove my 71 Challenger to work this morning and after driving about a mile

That's your problem. you should keep driving until you need to stop for gas. I have done that before and the wife would ask. Where did you go? My reply. No where! She would have that disgusted look on her face like I went to a bar. No smell of liquor or perfume. Or worse hunting or fishing! I would tell her if I did that I wouldn't be back yet!
No really check the grounds and see it that fixes the problem. Then we'll move on to the battery and charging part.