This is the point where I want to scream HELP!!!!

Recently my gauges pooped out on me. I would say a specific gauge but it's more than one all at once. One minute they're fine, then I start the car and voltmeter is dead with Gen light on. Then while driving to the parts house to get charging system checked notice that tach is not moving at all and stuck at about 1200-1500 RPM. Then I notice that the temp gauge is just over 100 degrees or so and not climbing at all. I'm in Arizona so I know that's not possible. Oil pressure hasn't moved since I got the car so not terribly concerned about that one at this juncture.

And yesterday I put 40 bucks worth of fuel in and the fuel gauge only read half a tank. Oh...wait...that's because fuel costs an arm and a leg...disregard.

From what I've gleaned from others by reading countless posts about gauge issues, I think I have a ground problem. However, I'm not even sure where to look. What ground would affect all of these things together? A description of how a tach behaves without ground described mine perfectly, but why and how are the other gauges affected?

As a side note, I put on a new higher amp alternator yesterday hoping I could just throw some parts at it and get results (yes, yes...I know that almost never works), so my alt is shiny and new. Besides, the car never showed indications that the charging system was not charging even though the voltmeter reads nothing and the light is on.

I know that I have a wiring problem but have no idea where to look. Checked fuses, of course, but all are fine.

Any help would be appreciated.

 

How about any of the fusable links?

 

If you have a late 70's/80's C3, you problem is likely a bad gauge circuit board.

 

Or the harness connector is loose.

What model year, po'boy? Do you have the chassis service manual or the AIM?

 

It's an '81. Sorry, forgot to mention that.

 

All I have is a Haynes manual which is no help. Need to get an AIM.

Pulled out the cluster and found one of the contacts where the harness plugs in is torn (top left contact if you're facing the back of the gauges). According to the meter this wire on the plug is grounded as is the one across from it. Would this also affect my tach? I'm assuming so because when it all worked and I had a weak alternator my voltmeter and tach would both tick a little when I'd use my turn signals.

Either way I need a new printed circuit.

 

Unless you can repair the one you have....

 

Is the copper strip itself torn...trim back the clear sheet insulation......then......use a "cold soldering" gun to repair it....then super-glue everything back in place.

I think that all the ground wires to the gauges join together in the dash wiring harness to a large ground wire which is bolted to the steel frame ?somewhere?.....it could be loose/corroded.

My '68 gauges each have their own ground wires, and went bizerk when the frame ground became loose!