Gauges Not Working

[tripz]

I'm in the process of fixing/buying a 1978 CJ5. I've got it running and everything works EXCEPT a few gauges: everything in the speedometer display. The speedometer itself, the temperature gauge and the gas gauge do not work. Everything else works.

All the wiring seems to be fine and like I said, all the other electrical components of the Jeep work fine. It's just everything in the speedometer display.

Get a new speedometer? Speedometer cable? If anyone has any suggestions, I'm open to them. Sorry if this is a n00b question and thanks in advance for any help.

 

[Turbogus]

Bravo tripz, rally the '78's~! Great find with a hard top, difficult to find in my neck of the woods. When I acquired 'Black Betty' (also a '78) first thing I had to do was address grounding issues, despite there being very little rust, I had to take one of those toothbrush shaped wire brushes to the back of my dash where the speedomter mounts and everything started working.

 

[Ggg]

Well the speedo is a mechanical cable driven unit. It is very easy to remove it from the back of the transfer case and use a drill to spin it and see if the speedo works. If not it is either a broken cable, or gauge. The other gauges are electrical. Typical electric gauge trouble shooting applies; check for voltage and ground to each, as well as ohm readings.

 

[Turbogus]

Agreeing with Ggg, what I found on 'Betty' was the speedometer cable was resting against the hot engine block, thus drying out the lube in the cable and leading to failure. The new cable I protected with fuel line as a sleeve.