Fuel Gauge Blues!

[Guest 68vwdubb]

My fuel gauge on my 90 has a mind of its own. The tank is full and the gauge flashes empty. One time you start the car it shows full and then the next empty. A few times I started out driving with it showing full and then a few miles down the road it goes to flashing empty?? Any help greatly appreaciated.

[Ronnie]

Bad connection or bad sending unit in the gas tank can cause this problem. If it acts erratically with any amount of gas in the tank then I would suspect a bad connection. If this only occurs when the tank is full I would suspect a bad sending unit.

[Guest 68vwdubb]

Hello TDman,

Thanks for your help. I didn't know If I would possbily have a cluster problem or what. thanks mike

[Barney Eaton]

This might give you a clue where the problem lies. There are three fuel gage connections at the tank. The problem is the connection is at the top of the tank.

* The wire from the gage is purple (per 1990 manual)

* The wire for 12V is pink/black

* the last connection is ground that is black/white (it is possible that you have a poor ground)

You could first start by grounding the tank and see if that helps.

Connector C419 is under the car, near the fuel tank. The manual says it is 5 cavity, but another reference shows 8 and appears to have at least the pink/black and pink/black wire, it may also have the purple wire. I will also have the power for the fuel pump.

If you can unplug this connector, you can test for 12V coming in on the pink/black. Find the purple wire and test it grounded and with 12v to it, this will cause the gage to read full one way and empty the other.

Don't forget to have the ignition in the ON position to test for power.