Gas gauge stuck WITH new sender??

FlaCarrera · 07-11-2002, 11:29 AM

Second car glich of the day. New gas tank sending unit installed today. Gauge STILL stuck @ 3/4 mark. Lots of posts about freeing float etc, but this has mechanic & me puzzeled. A "bad" gauge wouldn't register at all or move I would think. Contacts are clean. Any ideas?

Thanks
Ted in raining once again in So. Fla
86 Carrera Blk/Blk
PS Thanks to board responses on earlier question re headlight relay.

Early_S_Man · 07-11-2002, 11:47 AM

Ted,

If I am reading between the lines correctly ... the gauge stuck at the 3/4 mark was why you replaced the sender, right?

Assuming you still have the original sender, could you measure the resistance with that original sender at empty ... i.e., sitting on a table, upright? and another resistance reading with it inverted, or in the full position???

With those readings, get a potentiometer slightly larger, but in a 'standard value' ... 1K Ohms, 5K Ohms, etc. ... and substitute the potentiometer for the tank sender. If you sweep the potentiometer through its' range, and the gauge still sticks ... time to repair or replace the gauge!

FlaCarrera · 07-11-2002, 11:55 AM

Warren,
Correct, that's why we replaced the sender. Great tip now being forwarded to my wrench. As fuel is used, gauge descends downward from 3/4 indicated which makes me think it's something other than a bad gauge. Oil Pressure side works fine.
Thanks
Ted So Fla where the rain has now stopped.
86 Carrera Blk/Blk

ChrisBennet · ChrisBennet's Garage

I just replace the sender in my '86 last month. On my car at least, the value should range from a few ohms (1-5?) empty to 71 ohms full. I could flip my sender upside down and it would seem to work. (Incidently this is much easier if you take the sender out of the car first.

) But it wouldn't work in the tank. I had my sweetie get in the car and watch the gas guage while I shorted the leads briefly and she saw the needle pegged (full) so I knew is was the sender.
Hope that helps,
Chris