Fuel gauge goes right to full when the key is turned on. Had the gauge assembly out of the truck very recently and refaced three of the gauges and installed a new (NOS) temp. gauge. Everything working fine except the fuel gauge, worked great before the new gauge facings were applied. Carefully marked the wiring prior to taking the gauge/speedometer assembly out of the dash so the install would go smoothly. Took the time to double check everything when it went back together, all wires went back to the same spot where they were taken from. I'm sure this kind of problem was discussed back in the archives someplace, but if anyone has a thought on it, please share.
After tear down and assembly I had multiple issue with the fuel gage. After weeks of troubleshooting I discovered that painting the inside of the housing in Not Good. I removed the painted surfaces inside of the housing and all my fuel gage issues were resolved. Hope this helps.
How does the fuel guage mount behind the dash? Does it go fuel guage,back panel,, nut, then metal/cardboard divider part, connections,then nut? I am getting ready to install mine and I dont want to fry it.
FWIW, I found the problem that I was having when I first started this post. Turned out to be the wire from the tank sending unit to the gas gauge was bad. Replaced it and we're good to go. Fortunately an easy fix.