backwards gas gauge

[troy6187]

here's the story guys... awhile back i put everything from a 94 cherokee in my 88 mj. motor, tranny, transfer, and all wiring and associated stuff. my fuel gauge now reads in reverse and is not accurate. i know this is because chrysler changed something in the sending unit/ gauge. installing an older gauge in the newer cluster will not work as the mounting is different. does anyone have an idea as to how i can fix this!?!?!?!?!?

 

 

if i have to i will make custom cluster by combining both. would rather not do this as it will be very time consuming and a pain in the you know what.

[88XJSport]

In 91, when everything went HO, the sending units reversed...I believe you have to swap 2 wires pertaining to the fuel pump, but since I vaguely remember which ones exactly, ill let someone else chime in.

[chicofuentes0224]

Supposedly you switch the wires around on the sending unit in the tank.

PM Hornbrod, he knows for sure.

[HOrnbrod]

In 91, when everything went HO, the sending units reversed...I believe you have to swap 2 wires pertaining to the fuel pump, but since I vaguely remember which ones exactly, ill let someone else chime in.

 

The polarity of the sender was reversed in the 91+ as stated above. There is a 3-pin connector on top of the fuel tank. The sensor (variable resistor) outputs to the gauge are pin A (ground, BLK wire) and pin B (variable resistance out, BLU wire). The wire colors may be different for your model, but the pins should be the same. Swap these two wires and it should work correctly. It still will not be 100% accurate because the sensor resistance values are different between the two, but at least the needle will go in the right direction. :D

[Eagle]

In 91, when everything went HO, the sending units reversed...I believe you have to swap 2 wires pertaining to the fuel pump, but since I vaguely remember which ones exactly, ill let someone else chime in.

 

The polarity of the sender was reversed in the 91+ as stated above. There is a 3-pin connector on top of the fuel tank. The sensor (variable resistor) outputs to the gauge are pin A (ground, BLK wire) and pin B (variable resistance out, BLU wire). The wire colors may be different for your model, but the pins should be the same. Swap these two wires and it should work correctly. It still will not be 100% accurate because the sensor resistance values are different between the two, but at least the needle will go in the right direction. :D

^^^

 

What he said.