View Full Version : 03 Prostar Fuel Guage

06-12-2012, 10:56 PM
I replaced the sending unit a couple of months ago and everything was working great until last weekend. My gauge is now continuously moving as if the sender is trying to calibrate itself. I get the same result with just the ignition on and the engine running. Voltage measured at the harness for the sender is steady which suggests to me that the gauge is fine. It is a 3 wire sender if that matters. Thoughts?

06-13-2012, 09:15 AM
check the resistance of the sending unit - s/b 240ish when empty and 30ish when full.

06-13-2012, 10:45 AM
Thanks for the reply. Do I take the reading with the ignition on or off?

06-13-2012, 10:54 AM
on .........

06-14-2012, 01:54 PM
Thanks for the info...I'll grab some measurements this weekend. The other hypothesis is that there is a problem with the ground. Can anybody give me a basic walkthrough on how to test the ground? I am a rookie with the electrical stuff.

06-14-2012, 03:52 PM
Get a multimeter.... put the tester in resistance mode...touch ground on gauge with one probe the other on known ground...should peg needle on analog...on digital - there should be a continuity setting..it will be or something with good continuity.