shut off my '75 had lunch and restarted all seems o.k look at my three gauges ( dont count the clock anymore )..oil needle is pinned to the bottom,
temp wont move up at all,but amp seems to be jumping around as always.
shut off --restarted - same thing...any ideas ???? all 3 were fine before lunch.

 

On a 76, the gages and the power windows are on the same fuse.

 

My water temp gauge did the same thing, (pinned at 260). I replaced the sending unit but no luck. Do you know if there a separate fuse for this on an 81? All other gauges work perfect and the fuse was good.

 

I had some problems with my '81 in that area. The gauges all seem to be on the same fuse, but they are all connected via a horrible flexible printed circuit behind them. Some of the tracks are very thin & can easily break. One of mine did (without any help from me). The connector to this board can cause problems. Remove the gauge console (which is a lot easier to do than the manual implies) & use an AVO to check each track. I used a surface mount electronics soldering iron & low temp solder to repair a broken track. I also glued the connector tracks back onto the circuit where they had lifted & then cleaned them up with very fine emery. Well worth doing as all the gauges seem to give more realistic readings now eg. the water temp now sits at 180 instead of 150.
Also check for continuity from the gauge to the sender (could be a bad connector/broken wire).
It may sound like a PITA to do this, I wasn't to keen on doing mine, but once I got access to the printed circuit I was glad that I had. 20 years has quite a bad effect on those circuit boards & I'm convinced that a clean up & bit of soldering has offset a lot of future problems.
:cheers:
Paul

 

I am in the same boat...I need to tear into mine...temp is fine but the others need some investigating.....

 

I just fixed a very similar issue. Here's what I did:

After blowing out the flexible couplings at the starter (grounded alternator wire :smash: ), I lost my headlights and the gauges.

The headlights were a separate issue.

My clock, as yours, is a non issue. My oil pressure gauge was pegged, my temp gauge appeared to be fine (it wasn't), my fuel gauge appeared to be fine (wasn't), and my voltmeter was dead (reading zero). I pulled out the dash and the gauge panel. The printed circuit, after a lot of eyeing, was fine. Thank God. Those are expensive.

Then I took a multimeter and ran the course of the underdash wiring. After poking around and around, I touched my positive lead to the fuse panel (while ensuring a ground) and I heard a "click". I looked up, and all was well with my gauges. I pressed in on the fuse, and I have yet to experience this problem again.

My advice is this: get a multimeter, a wiring diagram, and poke around. You'll learn more about your car's electrical system, in a few hours, than at any other time. And whether or not you fix the gauges (you probably will) you'll be better off for it. Take my word.

I walked into this issue crying like a baby. Now I'm a man. I'm an electrical Jedi Knight. Or something like that. :jester

Give it a shot.

 

NOW WE HAVE NO TACH,NO POWER WINDOWS,NO GAUGES...
BUT CAR IS RUNNING FINE AAAGH !!!!!!

 

Use a multimeter to check continuity through the P. circuit. Mine had a hairline crack that was very hard to see - even when I knew where it was. The circuits can be repaired by soldering wire links to jump any breaks (use a low melting point solder & lots of care).
The tracks at the connector were the biggest problem on mine - as the connector was plugged into the console the loose tracks would move about. Sometimes 2 would short together causing all sorts of problems. I just glued all the copper tracks back down to the P circuit.
Another problem I've just found is that a fuse that had blown sometime in the past had melted part of the fuse box underneath it. The lump of melted plastic was preventing the replacement fuse from pushing in far enough to make good contact. Took ages to find that one, so it may be worth checking your fuses are making good contact with their sockets (still didn't fix the problem I'm looking for though!).
After wasting hours & hours trying to find gauge problems I'm now convinced the way to do it is as above ie. get a multimeter, a wiring diagram & pull out the gage cluster & speedo/tach cluster. Then spend some time just checking that ground wires do go to ground & all the power feeds give 12V when supposed to. With 1/2 the dash apart finding these problems is much, much easier. A few beers & loud music at the same time also helps
Good luck
Paul