Gauge problems

[vatree]

Highly technical support staff; I have a '71 J4700 and my gauges aren't working (fuel, temperature, and oil pressure) speedometer works fine. I have checked the fuse panel. No blown fuses located. Any and all help is needed. Thanks.

[jaw knee]

I'd check the grounds! there's a notorious one on the back/ rear of the frame drivers side..

[vatree]

Thanks for the response. I'm not sure of the exact area you are talking about. Are you able to describe it more? what color should the wire(s) be?

[Dirt Wag]

I had the same problem except mine worked SOME of the time. In my case I unplugged the round connector from the back of the cluster and carefully pinched each round pin socket to make a tighter connection.

[tkiller13]

I cant say for pre 74's but, the temp gauge could be at fault. It can make the fuel gauge not work. What do your gauges do, stay pegged one way or the other?

[RubiconMike]

I had the same problem except mine worked SOME of the time. In my case I unplugged the round connector from the back of the cluster and carefully pinched each round pin socket to make a tighter connection.

Did this solve your problem? I'm having a similar problem where my gas and oil pressure gauges sometimes work and sometimes don't. When they do work they are sometime accurate and sometimes not.

I noticed that according to the wiring diagram, one post of the gauge should have 12v and the other is grounded by the sensor. When I tested the terminal it only had 9 or 10 volts. When I supplied 12v directly to it, all the gauges pinned!

Anybody know what voltage should appear at the gauges?

[vatree]

All, thanks for the valuable input. My gauges do respond or show any readings. They all stay to the left. What colors are the hot and ground wires? Thanks.

[Driftwood]

Look at post #2. There is a network of black wires that are bolted to the frame. These are all ground wires for various systems in your jeep. Most likely corrosion has set in.

[vatree]

Are these set of black ground wires inside or outside of the cab. If anyone has a pic, that would be great. Thanks