91 fuel gauge question

[Keyav8r]

Do the 91 & 92 MJ and XJ use the same polarity and range on the sender and gauge? Or, more to the point, will a fuel gauge from a 91 XJ cluster work correctly in a 91 MJ cluster?

My sender checks out OK at the tank but the gauge never goes above 1/2 tank when filled up but the low fuel light works a low fuel level. I need to ID the wires at the cluster to check the ohm readings there and compare them to the readings at the tank, but thought I'd change the gauge first (if I can find one).

[mikekaz1]

Yes. All 91-96 XJ clusters will work in a 91/92 MJ

[Minuit]

That. Don't believe anyone who says a '96 cluster won't work. I've seen that load of crap a couple times on various Jeep forums. A '96 cluster works perfectly in my '91.

[HOrnbrod]

My sender checks out OK at the tank but the gauge never goes above 1/2 tank when filled up but the low fuel light works a low fuel level. I need to ID the wires at the cluster to check the ohm readings there and compare them to the readings at the tank, but thought I'd change the gauge first (if I can find one).

 

How did you check the sender's ohm readings at the tank, and what were they? Should be:

 

Empty - 105 ohms

1/2 = 33 ohms

Full = 5 ohms

[mikekaz1]

That. Don't believe anyone who says a '96 cluster won't work. I've seen that load of crap a couple times on various Jeep forums. A '96 cluster works perfectly in my '91.

yup I have a 96 in mine also

[Keyav8r]

Don - I dropped the tank to replace the vents. While I had it down I reached in through the filler neck and moved the float arm with a straightened coat hanger while back-probing the connector on the pigtail from the sender. Readings at full and empty were right in line with your numbers. I didn't simulate 1/2 tank. Probably should have. I guess I'll break out the wiring diagram and get my Vietnam era Marine avionics tech brother over here to educate me on the finer points of wire tracing and then check and clean every connector. Trying a different gauge is just a lazy way to eliminate one possible faulty part.

[HOrnbrod]

I dropped the tank to replace the vents. While I had it down I reached in through the filler neck and moved the float arm with a straightened coat hanger while back-probing the connector on the pigtail from the sender. Readings at full and empty were right in line with your numbers.

 

That's pretty impressive - didn't know you could do that.  :cheers: 

 

It does sound like the gauge itself could be the problem. If your circuit checks from the sender to the gauge cluster turn out okay I'll soon have a spare fuel gauge you can have.  

[Keyav8r]

There was 91 Cherokee in the B'ham Pull-a-Part that I'm planning on pulling the cluster from if it's still there when I get time to go by there. If it's gone I might just take you up on the offer.