Small Block & Big Block Chevy Specific - Weird problem?!?

My car has been acting up recently and i think it is due to an electrical issue, let me tell you what it does. When I first start it the voltage is often high like 16volts and after driving for a little bit it begins to fluctuate drastically. It often dips down to 10 volts and then randomly jumps up to 16volts again, I have changed the alternator to no effect 3 times. I have a weird ass looking solenoid on the firewall that everything is routed to and from, do you think this could be causing my issue? I would think that something is drawing mass amounts of voltage and then stopping and that is causing my fluctuations. There is no consistency to this problem and it is driving me insane, any insight would be helpful.
-Jeremy

Honestly, mine does the same fucking thing. Must be because we went to a carb setup, maybe there is somthing about there not being enough voltage used maybe? Hope somone here can help us shed some light.

Yeah it has always done this but recently it has gotten worse and Im afraid its going to burn up all my electrical items.

Do you have any weird looking solenoids under your hood zane?

Uhhh...which one, i have a few. Are you talking about the flat thing beside the brake booster?

Uhhh...which one, i have a few. Are you talking about the flat thing beside the brake booster?

No, I have a solenoid right in front of my fan for the heater, every electrical item is routed through it.

it happen to my 89 rs to, what was on my was my alternator, have youll check that, because when it is cool it will works fine but after it gets hot it will be going crazy,

Yea, that sounds right. I think mine does it when it gets hot too.

Mine does it when its cold too, like I said its inconsistent. What could cause this problem? If something was drawing and releasing power randomly it would cause this right?

factory gm gauge??? check the output of the alternator with a dvom to make sure your not chasing a charging system ghost .

factory gm gauge??? check the output of the alternator with a dvom to make sure your not chasing a charging system ghost .

Well the dash gauge and the gauge on my radar detector tell me the same, but I havent actually checked voltage at the alternator.

also look at the connector that plugs into the alt . see if there is any rust on that connector

Check as many grounds as you can find.

^^^ He has a poiny, with the engine in your car now did the heads have paint on them? I think that could cause a ground issue maybe? Clean some paint off the ground spots. Just a thought.

I feel like a dumbass now cause I found that I had one of my grounds hooked up to a piece of plastic!!:bang: Problem hopefully fixed...

:jest:


That is funny, hope it works.

Smokey, you ever figgure this shit out, mine has been stubborn at 9 volts and it is pissing me off, my fan cont come on as wel as my windows not wanting to roll down, i need to fix this shit, think i might have a shop i use for electrical shit have a look at her.

hey i know this is an old thread but that solenoid is your starter solenoid.