electrical help with gauge failure

[bart]

i have autometer gauges. i have the fuel level for 89-present ford. the other day i was driving, and i was messing with a little eclipse, well i put it on the mat and when i did the gauge pegged over to F, like way over past it down close to the screw actually. well i figured the gauge just bit the dust and went on. i hadnt had the time to pull it out and send it back to autometer. so yesterday i had this damn idiot in a cavalier riding my ass, so once again i put it on the mat after about 10 min of puttin up with them. well i look down, the gauges is TRYING to read. its bouncing back and forth across the range.

so what does this sound like to you guys? im thinkin its not the gauge, maybe the sending unit is bad? or maybe the signal wire has grounded out or burned up or something? what can i do to test to see what possibly the problem is? i have a voltmeter, but im not good with it, so youd have to tell me the setting to check for results. thank you for any help.


Bart

 

[HISSIN50]

i would look for a bad sender wire, as you mention. a lot of sender wires will peg the gauge hot when the sender is ground, so that sounds likely. you could set the DMM to ohms and check - if the sender is grounded, it will read very little ohms.
it may be easier to just check the wire where it runs through metal (i through back seat bulkhead, through trunk, etc and anywhere under the car where the wire is exposed). i might just run a new wire, especially if you can find that the wire up front is not damaged (saved pulling the cluster).
that is my two cents worth. good luck.