Fuel/Temp gauge issue

[1985 cj7]

Hello, I like many others am having an electrical issue with gauges. i Have read an un-measurable amount of posts over several different forums.

My issue is- fuel/Temp gauge not working

Treatments to date- All new wiring, new gauges, All appropriate and in good working order. All ohms/ voltage tests are correct. All grounds/ connections are patent.

Symptoms- Fuel/temp gauge only read when test short is applied or a test light is applied to the "A" (fuel guage) and the "S" (Temp guage).

Im an EMT so i apologize for the format, I found in reading many posts its easier to follow if i present my query this way.

Thanks in advance

 

[Torxhead]

Look up John Strenk's CJ gauge diagnostics page on the net, and report back.

 

[danray48]

I just went through that problem, I ran the test that John Strenk posted, and everything checked out as it should. My test light would flash on the "S" terminal, and the "I" and stay on on the "A". Checked all my grounds. New wiring harness. I installed a new gauge. I gave up and said, it has to be the gauge. I trouble shoot for a living, so that was my conclusion. I called Morris which was great, and they are sending me a new replacement speedometer. Last night while installing a new tach, I noticed a plug which has the pink sending unit wire in it behind the dash cocked a little. I squeezed it together, and there it was, my fuel gauge works. I,m not sure how the test I did showed power on the gauge terminals like it should, but it's working because of that plug. so I said all that to say that the problem is probably slapping you in the face, like it did to me, and you just cant see it. Go over everything, and use John Strenks guide to trouble shooting the gauges. It's priceless..........

 

[grozam]

I had the same problem with the test light not flashing, but lit. I replaced the sending unit and rewired the gauge and now it works .