why wont my fuel guage work ?

my fuel guage wont work on my 1975 3 series , i've checked all that all the wires are ok and cleaned all the terminals . i also grounded it against the tank and the fuel guage went up to full .

what does this mean ? do i need to buy a new sender unit ?

Sounds that way, fella. You could always double-check the tank is well earthed - although they're bolted directly to the chassis they can rust heavily along the mounting.

Consolation is that they're pretty cheap, dead easy to change and you should have really good access to the sender (unless someone has fitted the wrong seats).

yeah its real easy to get to the unit i had it out today checking it out , can you confirm the best way to check that its got a good earth , im still learning :confused2:

Happened to me last week, i earthed it it went to full, so i thought it was the sender, cleaned the terminal and the spade, put it back and it worked fine, sprayed it will electrical cleaner, it could have been a bad earth from from the sender as you screw it in to the tank, you have a rubber seal there, i took all that off and gave it a clean with a wire brush then put it all back, then again it could have been the unit had stuck, as i was off roading on very rough terrain

does look fun

Not sure if i was stuck, or throwing up from the night before.....a had a beer.....or 2