Dear Elbee,

May this find you well. While the instrument cluster and the window switches ground at the same point - that next to the engine control unit [behind the kick panel, on the door-side of the front passenger footwell] - I think the malfunctions are coincident, but not linked. If this ground point were corroded, other instruments would be affected, and none of the window switches would work reliably.

The fact that you can raise the left rear window using the switch closest to it, but not by using the switch closest to the driver suggests the problem is in the driver's window switch cluster. You might want to remove the cluster from the door, and clean the contacts. Optimally, you'd have a spare window switch cluster, and substitute that for the in-place unit.

The gas gauge malfunction could be cured by snugging the screws, that secure the gauge to the flexible circuit card. That requires removing the instrument cluster. See the FAQs for the "how to". If you pull the instrument cluster, check all screws, to be sure they're snug. The fuel and temp gauges are held to the circuit card by three screws (if I recall correctly). If the heads of these screws show signs of corrosion - green patina (the screws are brass) - then remove the screws and clean the under-side of the heads. This will ensure a good connection to the circuit card.

Please post back with your findings.

Hope this helps.

Yours faithfully,

Spook