I don't know for sure about the Berlinetta. But on my 1985 Z-28 I would pull
off the front bezel on the instrument panel. On the Z-28 the gauges have
mounting screws but the gauges just plug into the connectors. I would pull
out the Ammeter and check for corrosion or loose fitting. On the Z-28 it is
a pretty easy thing to do so I would check that first. It sounds like you
just have a corroded or bad connection some where to me.

It could be much more difficult on the Berlinetta though since they can be a
lot different than the Z's.

AA

Couldn't be more right there...total digital instrument cluster, only
available in the 84-86 Berlinettas. Like the stereo, left & right control
pods (surround the inst. cluster), the heater blower motor relay, etc, etc,
etc...

As far as I know, te cluster is a solid unit, but if you're right, that's
a LOT beter option thanspending the next few years looking for a parts car
with a functional cluster. NOT FUN!!!

I'm looking at a parts diagram of the digital 84-86 instrument panel. Not
many parts! It looks like the Volt/Temp gauge and the Oil/Fuel gauge plug
into the dash case separated from the speedo and the rest. If that helps
any? It could be corrosion in the plug area, or not. My Camaro has had
many electrical problems with most being corroded terminals.

AA

Yes, that's understandable. Had a hell of a time finding another blower
motor relay a while back, and the reason there was trace separation from the
PCB of the unit...all the parts are fine, but since you can't get the boards
to move the good parts to...

Maybe I'll pull the cluster and see if it is just dirty plugs...at least
it won't cost me anything!

Thanks for the idea...