I have had my 94 s10 blazer for about 3 years. The entire time, and before that as well according to the previous owner, the voltmeter bobs between normal and overcharging and all interior and exterior lights flash up and down. Obviously it's most noticeable at night but I can see the voltmeter bobbing, I would say 95% of the time. Sometimes they flash really fast and sometimes it's a slow and deep flash. Sometimes it's barely noticeable on the voltmeter while other times the bobbing intermittently triggers the warning battery light on the dash.

Here is what I have replaced both in response to the problem and through normal maintenance with no change in the symptoms: Battery, alternator, negative battery cable, battery-to-chassis ground, engine-to-chassis ground.

It was suggested that there was a grounding problem but the most obvious places are not causing the problem. Any suggestions guys? This is a very annoying problem.

 

a loose/bare wire somewhere touching something else would be my best bet. u'll have to go thru ur wires and check them.

 

I would start pulling fuses one at a time , then start it up and see if the flashing stops , if you
find which circuit is causing the problem you'll know where to start looking for the bare wire or
bad ground. Of course a couple of the fuses may be needed to allow the engine to run , but
the rest could be pulled.

 

I actually remembered that the cruise control had been flaky/not working since I've had it. I pulled that fuse and no more flashing! Unfortunately it's connected to the gauges and a few other things. How can I disconnect the cruise control only? The Chilton's manual says it's for 94 and up but it sure looks like 95 and up so it was no help.

 

Updated...I wiggled all the wires under the dash and couldn't make anything change. I disconnected what I assumed (blinkers and wipers still worked) was the cruise control plug inside the steering column and the 2nd larger plug a little bit further down under the dash. That also did nothing. Pulling the gauges/cruise control fuse still fixes the problem aside from disconnecting all the gauges. Does anyone have any specific "It's definitely between 'here' and 'here'" advice? It looked like the wire loom went right through the firewall after the steering column. When does it go to the fuse panel? Thanks guys.