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My 7 has a sporadically operating gas gauge. Most times when I start up the car the gauge works fine, but sometimes when I start the engine the gas gauge does not work…the needle stays in the empty position. However, it nearly always will start to work sometime during my drive….nearly always. On occasion the gauge will not work at all during a drive, but the next time I start the car it does work.

I have never had the gauge quit working during a drive. In other words, once the gauge starts to work properly, it continues to work properly until the ignition key is turned to the off position.

If the gauge is going to work on start up, it is usually when I turn the key to the “onâ€￾ position that the gauge wakes up, but this morning the gauge was dead…until I turned the key further to start the engine, then the gauge woke up.

I have checked the connections at the sending unit and the ground back there is good. Any thoughts as to the source of the problem? Perhaps a poor connection a the gauge cluster circuit board? A dodgy gauge or sending unit? A faulty “low fuelâ€￾ relay?


Kimmit

1980 DHC
GM 3.8 v6 fi

Have you done the first and foremost thing to the instrument cluster yet? ie: Fitted a separate ground wire connecting all
the ground screws/positions on the back of the cluster together, and then with a common (say 2 to 3 sq mm) wire to a
good ground position on the body. The oem solution is just simply inadequate with age and the connectors are usually
substandard with high contact resistance...

Mine was totally dead when I got my car. I cleaned the contacts on the sending unit two years ago and it started acting just like yours.

The car was on the rack right after I broke my foot in January, so I took the opportunity to check the connections. I pushed the connectors on better. Now the gauge works fine.

I have noticed that the gauge is more likely to not work if the car has been parked out in the cold.

I will take another look at the connections at the sender, and I'll upgrade the ground for the gauge cluster.

Thanks guys!

Kimmit

1980 DHC
GM 3.8 v6 fi

Did you ever try tapping on the dashboard when it's not working?

I had a gauge that stuck, just like yours. Removed the clear cover on the cluster (I used to do it without removing the entire cluster) and pushed the needle, it started working. Turned off the key, turned it back on again, no movement. Push it with my finger, it goes up to where it was supposed to. And good rap would get it moving too ... (might not be a good idea depending on the condition of your dashboard)

But yeah, definitely check all the connections ...