1996 Buick LeSabre gas gauge

My 1996 fuel gauge stays in the full position even though bits not full.i took off the glass to the cluster and move the needle down to Empty, then turn the ignition in again and it keep going back to the full position. I got another pump and sending unit but it’s doing the same. The pump now have to be grounded separely for it to pump. I tried grounding one of the wires coming from the sending unit and the gauge goes to empty and when I put it on the the other wire it goes to full. What could be the problem?:slightly_smiling_face:

The first problem is that you need a wiring schematic for this car and you don’t have one. Get a factory service manual on eBay. The second problem is you grounding wires by trial and error which is a sure fire way of frying components. Your third problem is figuring out if the fuel tank should be grounded, the service manual will tell you this.

Look under the carpet on the driver’s side for the wiring harness there. It may have been cut into by debris or rust. Just move it around a little and see if that changes anything at the gauge.