Where is the ground for the dash guages?

1988 XJ.

Guages fluttering at odd times.

I'm assuming it's a grounding issue but the question is....where is the main ground for the guages?

Thanks.

Gages, and idiot lights, don't have grounds at the dash.

The power (from the ignition) runs to the gage; then the other gage wire runs to the sensor, which grounds to the block (oil p, coolant temp) or at the tank (fuel level).
Volt meter might be the exception, I don't know offhand.

So, your problem is possibly a loose wire or connector from the ignition switch to the dash.

Thanks.

Actually, the fuel level sender doesn't ground at the tank. Both the pump and the level sender ground through a black wire that feeds forward through the 3-wire harness and grounds somewhere well forward of the rear axle. But the concept remains the same -- power to the gauge, then through the sender to ground.

Try unplugging the multi-terminal connector on the back of the gauge cluster and plugging it in again. Over the years the contacts may have oxidized.

Actually there is a dash board ground, it called "G102". It is a #12 black wire and attaches the a metal bracket behind the lower dash cover, you know the one with the AC vent to cool the driver's legs, and about 3 inches form the driver's foot well courtesy light.

If you lay on your back and look up at the courtesy lamp you will see the point end of the screw coming through the bracket.

I recommend you take out the screws for the lower panel to get better access to the sheetmetal screw holding the ground to the bracket. Then clean up any corrosion and apply some ox-gard to the terminal and re attach. You can get ox gard at any hardware store/home center it is in the electrical section.

You can still get the 1988 XJ electrical troubleshooting manual from Techauthority. You will have to call them since they don't list stuff over 10 years old on the web site. The troubleshooting manual costs $20 and worth it's weight in gold for questions like this.

Martin

Martin - could you tell me where this ground is exactly. I didn't quite understand from your explanation. Thank you.

TexasComanche said:

Martin - could you tell me where this ground is exactly. I didn't quite understand from your explanation. Thank you.

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Might try and PM Martin--this thread is seven years old.

Forget PMing Martin. His description of where the ground can be located is quite specific. Read it again real slowly and go have a gander under your dash.

Intermittent dash tends to be the connection from the cable to the flex circuit used to run to all the dash gauges in the cluster. Pull the plug to the cluster and take a pencil eraser and go over the copper contacts on the flex circuit and put it back together again.