[Red_79_TransAm]

I would never start in the middle of a circuit. First I would verify I had a signal at the output. Next I would go to then end and see were the signal is corrupted. This case I would start pulling fuses and see when the problem stops. It sound like you have a ground issue somewhere. I would have your alternator checked. Voltage regulator bad? Try another alternator you know works. See if that changes anything.

Thanks for the response. This is a new alternator and it did it with the old alternator as well. I did pull each fuse, tested, replaced the fuse, and the pulled the next one and it did it with each fuse isolated.

 

[ZumpTA]

You haven't dropped a ground but here might be something to the corrosion theory, if so its going to be a PITA finding where that corrosion is. Probably in one of the blinker harnesses, but every ground point, connector, and socket in each harness needs gone over. The condition is very normal though and does not negatively impact anything. You can live with it, try and track it down, or maybe you can just slap an appropriately sized capacitor across the back of the gauge to even out the load and stabilize the needle.

I did say all of my GM vehicles did/do this and I consider it a "GM thing", but on further thought, every GM i've owned but one was at least 5 years old. My '96 Corvette which I said is the worst of the bunch does have some corroded grounds. The car is a grounding nightmare actually. The one GM vehicle I had from new might have done it but I don't recall.

At the endnof the day, it's down to how much it bothers you. If it's an OCD thing for you, definately try to resolve it. Otherwise, just let it be and move on to another project.

 

[EdKnecht]

All I’ve ever owned is gm cars and trucks and never had this issue and I live in crappy over salting Illinois. Personally I refuse to accept its normal behavior… now if you had a big sub amp pounding away you’d see your headlights pulse.

 

[GaryDoug]

I would never start in the middle of a circuit. First I would verify I had a signal at the output. Next I would go to then end and see were the signal is corrupted. This case I would start pulling fuses and see when the problem stops. It sound like you have a ground issue somewhere. I would have your alternator checked. Voltage regulator bad? Try another alternator you know works. See if that changes anything.

Obviously you have never done serious troubleshooting. You start at the middle for a reason. It is assumed the signal is good at the front and bad at the end. Then the middle divides your journey in half. Bad at the middle, you move toward the front. Good at the middle, you proceed to the end. Trust a 50+ year electrical engineer about it. Logic is your friend even though some people don't understand logic these days. Pity them.

 

[EdKnecht]

I don’t know, I’ve repaired electronics for 20+ years…..always started at the source. Verify power supply is correct and have proper voltages where they are supposed to be. Then move down the line….looking for bad wires, circuits, corrosion etc… you don’t just jump to the carb without knowing you have gas in the tank . Sorry if this sounds argumentative

 

[GaryDoug]

I don’t know, I’ve repaired electronics for 20+ years…..always started at the source. Verify power supply is correct and have proper voltages where they are supposed to be. Then move down the line….looking for bad wires, circuits, corrosion etc… you don’t just jump to the carb without knowing you have gas in the tank . Sorry if this sounds argumentative

Hey, Whatever method works for you is good. It may not be the best attack, but that doesn't matter if you get it fixed. I have known a lot of wild guys in the business that succeded against all odds ;-)

 

[sleepyhollowtaman]

Obviously you have never done serious troubleshooting. You start at the middle for a reason. It is assumed the signal is good at the front and bad at the end. Then the middle divides your journey in half. Bad at the middle, you move toward the front. Good at the middle, you proceed to the end. Trust a 50+ year electrical engineer about it. Logic is your friend even though some people don't understand logic these days. Pity them.

I am an engineer for 50 years and would NEVER start in the middle. Always start at the beginning and work your way to the end. If it works for you, awesome. Just not how I would do it.