Cadillac Repair: 1986 Cadillac Brougham Fuel Gauge, cadillac fleetwood brougham, cadillac brougham

Question
Hi,
I have a 1986 Cadillac Fleetwood Brougham and the fuel gauge doesn't work.I replaced the fuse which was blown and it still didn't work. I replaced the fuel gauge with a used one and it STILL doesn't work! Any advice will be most appreciated!
Thank you,
Doug

Answer
Hi Doug, Here's what you need to do. First make sure there is battery voltage at the GA-TRANS fuse useing a test light or voltmeter. Then go undernieth the rear bumper and you will see a 6 wire connector. If the gage shows empty all the time with the key on unplug the connector and if it now reads full you have a black ground wire problem or the sender inside the tank is bad.
If the gage reads full all the time with the key on disconnect the connector and jumper the pink to black(A to B) or pink to a good body ground and if the gage shows empty the ground wire is bad or the sender is bad.
If neithor help then there is a bad wire somewhere in the circuit and needs to be found. The PNK/BLK wire terminal 1 at the gage should have power, term. 14 BLK wire is grounded and term. 18 PNK should have a variable resistance between 0 and 90 ohms depending on fuel level. Getting a wireing diagram would help and if more assistance is needed let me know. Bill