Electrical Gauges all peg when key is turned on

[TNcowboy]

Hi everyone
Longtime CJ7 owner that is planning to get her back on the road. It's got a AMC 258 i6 / 4.2l engine
When I turn the key in the run position all the guages peg to max. This is the original cluster.
It g as been in the garage for the past 10 years; everything was working great the last time I drove her.

Any trouble shooting help you all can offer would be great

Thanks ahead of time
Michael

 

[TSB8C]

First thought is the jumper that connects between the fuel and the temp gauge. The fuel gauge takes in power on the 12V terminal and runs it through a filament (the jumper) that moves from "contact" to "no-contact" as it heats up (during contact) and cools (during no contact) - this regulates power for both gauges (regulated power is sent to the temp gauge over the jumper). If the filament gets stuck in the "contact" mode - both gauges will peg.

Now if the volt gauge is also pegging out, you have a short somewhere. That one has nothing more than a yellow ignition (key on) wire +12V source and a ground. Nothing else interacts with that one to regulate anything.