temp and gas guages

84 cj7. Cranked it and the temp and gas guages don't work today. At first I just noticed the gas guage before it warmed up and thought it might be a sending unit, but after driving it a while the temp never moved. Any ideas? Need a new speedo unit?

 

Here is a site worth reading

http://www.jeeptech.com/electrical/gauges/

 

My temp guage worked fine, then worked intermittently, then quit altogether, then intermittently. I cleaned the wiring on the back of the guage, the posts on the guage, removed & cleaned the sending unit, all to no avail. I was clueless. Then I had a lightbulb moment. I unplugged the connector in the harness, scuffed up the contacts on each end of the connector as best I could (which wasn't very well) put it back together & Voila!!! IT WORKED and has ever since. Since both guages are inop, I am guessing that is where your problem lies as well.

 

After reading this I did some inspection. Where the diagram says the jumper regulator strap goes, there is none, and both the nuts are gone. Maybe it fell off? I don't know. The rest of the diagram seems to be identical to mine, even the wire color, except the jumper is gone. Could this cause both not to work, and if so, where would I find one of these, or could I use something else to make it work?

 

Well that's not it. I looked a little better, and it was hidden. Both the nuts were gone but it was there. I replaced the nuts. I noticed that when I turn the key on the gas guage floats up ever so slightly. But when I crank it it goes back down. Sending unit? Resistor?

Would the gas guage not working cause the temp guage not too work because of the ohm sent to it?

 

Just curious if you tested the gauges like the article suggests. One bad sender won't cause both gauges to malfunction.

 

No. I can't find my tester.

 

I would buy or barrow another one and test as per the article. If I was to guess I would say it's the fuel gauge and something is happening between where the ignition source goes in and the "A" terminal where it comes back out to the jumper strap. That is of course only a GUESS, gotta go through the tests.