Jaguar Repair: Fuel Guage, fuel gauge, change over switch

Question
Hi, I have a 1987 XJ6 with the 4.2 engine. With the car off the fuel gauge reads empty. When I turn the key on it reads full. This happens no matter which tank is selected. I was told the sending units were bad, so I replaced them. This did not solve the problem. Both tanks are near empty, should be reading almost empty. Even with new sending units I can disconnect wires of sending units, gauge goes to empty, hook them up, goes to full (key on). A  local shop said the gauge is working, but I'm not sure? This problem happened gradually, both tanks same time. Sometimes they worked, sometimes not. Now they never read right. Help!

Thanks,

Richard

Answer
I have this problem also. Here is the problem, you have a bad connector on your fuel tank change over switch. You might try removing your switch and cleaning the contacts. It may or may not fix the problem. If you have the old sending unit, you can remove the switch and connect the sending unit with wires and see if it works. I did that and found that the switch connector was bad. I hope that this helps. Sam