Hey Guys im not very mechanical but my fuel gage is not accurate as when I fuel up its either showing empty or full and it will never tell me an accurate reading to whats actually happening so everytime i've been guessing and just fuelling up whenever. What's the best way I can go about this getting it working?
1.) Check that your gas tank IS grounded.
2.) Next time its good and empty, remove the sending unit. Is it OK? You can get a good replacement on a 66 gas tank for under $50, if you look a little.
3.) Check the voltage coming from your dash at the BLUE wire, connecting to that sending unit. Is it 5-6V? If not, you need a new dash voltage regulator. There are solid state ones now, for again, around $50 I think, or you can get another electro-thermal one like from Standard for ~$10-20. I'd get the solid state one if I needed one. You will need to remove the instrument panel to get to that regulator. That requires a little head standing and contortion. I've done it, and still can, Deo gratias, but not everyone is so blessed.
Instead of mucking with that stuff on my '66 dash, I bought a nice new Autometer fuel gauge made for old MoPARs, ran it on 12V w a new sending unit and drove that car until it was destroyed by an evil succubus last September. I still have the gauge, and plan to keep it until I need it again. It ran me about $60 from Jegs.