Join Date: Sep 1999
Location: Boilermaker Country USA
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Toubleshooting a fuel tank sending unit
This has been biting us for along time. A flakey reading of the fuel gauge level. Even replacing the entire gauge cluster, still getting an inconsistent fuel level reading from the standard size tank in my 85 CJ.
Here are the symptoms of the sending unit as I understand it. The sending unit provides a resistance of 22.7 ohms and an approximate reading of a half-tank of fuel on the fuel gauge. This operation continued for about 15 minutes and then the fuel gauge was reading well below empty. A resistance measurement on the sending unit showed OVLD or basically an open circuit, i.e. infinite resistance. This state of operation lasted for about 40 minutes and then a resistance measurement of 22.4 ohms was obtained. Does this mean the sending unit has a fault or is there something else wrong in the circuit?
What do you think? Thanks!
1985 CJ with a transplanted 94YJ 4.0L motor, T176 tranny, mainly stock otherwise. ><>