TheoJ

The pictures you see are for the non-digital dash. Yours is a 1990 and is a bit different.
You verified that the 12v on the instrument panel is correct? It sounds a lot like the bad connection problem at the brass studs that connect the instrument to the dash panel (pcb or foil). Sure you did check and clean that?

Maybe the voltage instrument gets stuck mechanically? Dry, lack of lubrication? I would consider putting it on a testbench, adjusting the voltage up and down a few times and verify that it moves smoothly. If you have access to another unit, try replacing it. It is a pain to open the dash repeatedly

regards,

928Myles

Still chasing this issue.

On occasion the gauge reads correct for a while after start up. Most times it still reads low (

928Myles

Can't seem to get what I type to appear on the post - will try again later...............

928Myles

Still chasing this issue.

On occasion the gauge reads correct for a while after start up. Most times it still reads low (11.5V)

Usually when I turn on the park / side lights the gauge jumps to 12.5V, but not all the time.

I have cleaned (with deoxit) all CE panel relays, fuses & connections, grounds, pod connections & grounds, 14 pin connector.

Any bright ideas out there.

Thanks,
Myles

Dave H.

wow. not very high on the priority list, eh?

928Myles

Not high priority as it doesn't stop me enjoying the car but I am getting nowhere with regards to resolving it. I have run out of ideas and things I think I can try.

Myles

merchauser

BUMP
At start up, and for about the first hour of driving, my gauge will read properly, and match the measure voltage at the hot post. But with further driving, and higher ambient temps,
the gauge will read nearly 2 volts lower than the measured reading. (voltage reading at hot post remains the same, and good: 13.78v) This behavior is very consistent: I like the simple issue of replacing the resistor, but Sharkskin in post #15 mentions
this resistor is not related to the volt gauge? I need to replace some burned out bulbs so I will be removing pod, but no idea how to proceed.

Wisconsin Joe

Purely a guess, but I'd make sure all of the connections are nice & clean. DeOxit (Stan Spray) is your friend here.

If the connections are marginal, increased heat will increase resistance. That might make it show lower.

merchauser

^^^^Agreed. When I take the pod out I will Deoxit everything I can. I assume you mean the wire(s) at the volt gauge are getting hot? is the heat originating from the alternator?
and if cleaning does not resolve, is there something I can add, like a resistor, to correct?

Pretty confident I do not have a loose connection because rough roads and speed bumps have no effect on the gauge. Happen again this AM: cold start and first hour or so of driving,
all good, then goes downhill. Clearly this is only a nuisance, and not a true problem, but I would like to clear it up.

islaTurbine

I have a similar issue on my ‘78 but I haven’t investigated it yet.

Sportie

I have had this issue for two years and fixed it last week. I did nearly everything that has been mentioned on here and had almost given up trying to fix it. However last week I took the pod apart again and removed the gauge cluster and stripped it down. The problem was that the gauge was very stiff, if you move it up with your finger it should move with very little resistance. Once you let go of it, it shoots down. But in my case it took quite a bit of effort to get the gauge to move up. so I sprayed it with a quick drying contact cleaner. This was sprayed into the gauge whilst gently moving it. Imediately the initial resistence had gone. Putting it all back together it now works perfectly, shows 12 volts as soon as the ignition is turned on and shoots up to 14 with the engine running. Before I was lucky to see it showed 12v after a few minutes and it never showed 14v in the two years I have owned it. Hope this helps others?