View Full Version : fuel gauge always reads full

Greg Nilles
07-03-2010, 08:39 PM
My fuel gauge always reads full. Any suggestions? The send unit or the gauge?

1989 Prostart 190.

07-03-2010, 09:17 PM
Sending unit magnets are loose or the float is hung. Do a search on here. There are pictures and information on how to check the gauge and repair the sending unit. Not hard to fix. Took me less than two hours and I spent most of that letting the super glue dry. Plus order a new one if yours is junk.

07-04-2010, 06:21 PM
Take yours out and measure it, then buy new.


07-04-2010, 07:04 PM
Try to narrow it down to the sender or gage. On my first car a Jeep CJ-7 the sender was OK but the gage was bad. I used a multimeter to check the fuel level. I would start there. Check resistance across the sender terminals. Then rock the boat which will cause the float to go up and down and watch for the resistance to change. If you see this then it is the gage. If you see nothing or no changes in resistance it is the sender.

07-04-2010, 11:40 PM
Do a search on this web site. The magnets are famous for coming loose. It doesn't matter if the float moves or doesn't move if the magnets don't. This is a easy check and there are pictures on this web site. Unplug the gauge leads from the sender--gauge will go to empty. Stick the leads together gauge goes to full or visa versa. If gauge moves it ain't broke. It might still be off but it ain't broke. Like suggested above you can order new. Delivery by normal shipping for me is a week. I fixed mine in less then two hours and it is still working a month later. You have to have tools, a little luck, and good super glue if it is the magnets. Also you can sand the float just a hair and it slides up and down the tube better. Your money--your time, but search this web site. There is a wealth of good information.