Landseer

(fixed, starting on post # 17, broken wire inside 14 pin connector)

Our 86 voltage meter jumps almost always, non-stop. Usually between 10 and 12 volts. Stuccato. Never had any problem charging the battery from a practical perspective. The car is apart (had to fix a tensioner oil leak), so I want to take an opportunity to trace this problem.

Problem has existed since we rescued the car.

Have tried other known-good alternators, no change. Every alternator we try works on the other car perfectly, and charges on this car also, but this gauge keeps bouncing.

14 pin connector is clean. Fuse box is clean.

Should I dive into the pod?

Alan

What does a seperate voltmeter say - stable or also bouncing up & down? No point changing the alternator or anything else unless the voltage is actually unstable - maybe its just the gauge?

If its the guage it may be a connection issue inside or outside the guage...

Alan

Landseer

Thanks, Alan.
I'll try inserting another meter in the circuit and report back.

surfdog4

i had the same problem on my '81..it's possible that the contacts on the flexible circuit on back of the cluster are bad..either at the connector or elsewhere on the circuit. Once i bypassed all the "edge" connectors with pin-style connectors all my gauge problems went away

Landseer

Thanks.

Pin style? Did you solder them / adapt them to the flex circuit panel? What are they and how did you utilize? Did yours charge the car, just read poorly like ours.

NoVector

Mine did that once… It turned out to be a stuck window switch. I’m with Alan—confirm it with a separate volt/ohm meter. Maybe you could start removing fuses until it stops(?) At least you’d know where to start finding the problem. Good luck! / Bruce

6mil928

Mine does the same thing. I have a new ribbon in mine. The voltmeters are just crap. It reads great, it reads erratic, it reads crappy. Confirmed with a volt meter that the chevy alternator is charging fine at the battery. Anyone know if they are still available to buy new?

I'd also be interested in this pin style?

76FJ55

Mine is also doing the same thing. I have not had time to chase the cause yet though I am leaning towards some sort of bad connection in the instrument cluster. An odd corrolation I have noticed with mine (I'm assuming its odd but maybe thay all do it) is that when I push the ODO reset the volt meter drops to 0, then gives indications again once it is released. This technique can also be used to correct irratic readings sometime. Other times it goes back to wagging imediatly after releasing the reset button. I'll let you know if I come up with any remedies.

Chris Hansen

Mine does this as well. I've replaced the circuit board, and the resistor, but no change. Let us know if you find the culprit!

no doubt

Does your voltmeter needle jump around with the motor off but ignition switch set to Run (not Start)?

Landseer

No. Only when operating the car. Yours? Ideas?

Jadz928

Chris,
It's time for a pod-ectomy. Let me know when and I'll bring the eraser.

no doubt

Mine jumps a little right when the cooling fan kicks on, A/C button is pressed, lights are turned on, etc. In other words, at the beginning of a large power draw I see a brief twitter.

The suggestion above to see if pulling relays/fuses until the erratic voltage needle behavior stops has merit...but you apparently only need to be pulling circuits that are active when the motor is running since you can't get the funny needle jumping behavior otherwise, I'd guess.

surfdog4

I had a compound problem, the regulator was dead and the connections on the pod were flakey. I found a rebuilt alternator (the local auto parts shop couldn't test the alternator on their test machine) so i replaced the whole works.

As for the circuit board, I removed the crappy edge connectors and (carefully) soldered individual wires to each of the circuit tracks. I made a clamping mechanism out of cable ties to hold the wires down on the board so they don't try to lift off the tracks. Then i soldered the wires to MIL-spec D-shell connectors (got on e-bay). The fun part was cutting off the connectors on the car side and soldering all those wires to the D-shell mating connectors.

End result though was all my gauge problems went away. My speedometer would not go above 30mph, my temp gauge was dead, the voltmeter was oscillating, and my oil pressure was constantly pegged above 5. A couple of warning lights were on. Now everything is working fine. THe voltmeter will move some when you turn on big amp draw items, like headlights, because the voltage really is dropping (the stock alternators are just weaklings).

Also be sure your alternator warning light bulb is operational, the charging circuit for the alternator passes through it.

jpitman2

Mine sometimes jumps to 16V while driving, but a separate DVM plugged into cigar lighter reads a more normal voltage, like 13.8-14.2, so I am just waiting until its time to pull the pod and clean connectors.
jp 83 Euro S AT 52k