Fuel gauge only working sometimes

[mshred]

I am about at my wits end with my gas tank.. This season my gas gauge decided to stop working- I put a stiffer spring in the reostat, made sure all my grounds were clean and proper, wiring to the gauge is fine, etc....I had an issue with the float not floating (this was an aftermarket sending unit), so I swapped in the brass float from the original sending unit....All was well for a few days, then the gauge decided to only work sometimes- while driving it might read, then all of sudden drop right to empy and not come back on until I shut the car off for a few hours....Now its not reading at all!!!

Wondering if I should just pony up for another new sending unit even though this one is only about 1.5yrs old...this gas gauge stuff is driving me nuts, and it already left me stranded once on the street! Tired of it controlling how I can drive the car, so was just wondering if anybody had similar problems or what I could try next to fix this.

Thanks!

 

[RedFish]

If the temp gauge also stops working the gauge voltage limiter may be the culprit. These gauges and limiters do loose connection to the printed circuit board due to corrosion, and vibration.

 

[67Dart273]

You need to try and catch this when it's not working, and don't move the car. Access the sending unit (easiest) by removing the left kick panel and separating the connector. Check the ohms reading from the sender wire to ground. A high or open reading means

Either a problem in the sender wire (end connector probably)

An ungrounded sender

Or a bad sender.

If you are getting a reading "somewhere in the range" the gauge would "like to see" then the trouble is up towards the gauge. (10 or so to 73 or so ohms) Don't discount "simple crap." On mine the fake nuts on the gauges were not making contact on the gauge studs

 

[momoparman]

You can also have a problem at the large round pin connector on the circuit board itself. As stated before, wait until the problem happens then stop immediately and reach up under the dash and try to wiggle that big round connector to see if the gauge starts working. I have had the same problem before and replaced everything only to find out it's just a bad connection at that plug.

Good luck the circuit is very simple so it can only be a few things causing your problems.

 

[67Dart273]

You can also have a problem at the large round pin connector on the circuit board itself. .

Exactly. Which is why I suggested checking, as to separate the problem into front/ cluster? or rear/ sender?

There is "not much" that is NOT common to all the gauges, IE temp / fuel, or temp / fuel / oil in case of a Ralley cluster.

The gauge, the studs at the gauge or the pin as mentioned for the sender wire. I spose it's possible even the gauge itself.

MAKE CERTAIN the temp gauge is unaffected.