Fuel gauge

[Wounded_Fighter]

So replacing a seal on the fuel pump I managed to break the gauge sender on the pump.. went an bought the new unit at the nearby Zone "Pump here", and without even thinking about it too much, shoved it in the tank. I must admit it was a very tight fit...  struggled a little bit, but got her in and secured properly, eventually. Lol

 

But... to my dismay the unit is somehow reading the fuel level in reverse... I noticed it throughout the day as the level keeper getting closer to full.... so I tested the theory by adding some fuel to the tank, sure enough went towards E as I was filling it. 

 

Soooooo my thought/question is this....

Is there a was to reverse it on the back of the gauge that might be easier than pulling the unit out of the tank... again...

[87MJTIM]

You got one for an HO engine. The polarity is the opposite for a Renix. 

[sinkrun]

New comanche ones for renix are no longer made

[Wounded_Fighter]

14 hours ago, 87MJTIM said:

You got one for an HO engine. The polarity is the opposite for a Renix. 

 

So... could it be re-reversed? lol

 

autozone pulled it up as an 88 comanche, there is a similar one for 88 cherokee, 1 digit difference.

the comanche one was CHP10148 and the cherokee was CHP10147 think there is any difference in these?

[Eagle]

I believe the arm for the float swings to the opposite side for the Comanche and the Cherokee.

[Eagle]

15 hours ago, Wounded_Fighter said:

 

So... could it be re-reversed? lol

 

autozone pulled it up as an 88 comanche, there is a similar one for 88 cherokee, 1 digit difference.

the comanche one was CHP10148 and the cherokee was CHP10147 think there is any difference in these?

 

AutoZone is, as usual, screwed up. They tell me that this part fots an 87 Comanche 4.0L, and they tell me it fits a 91 Comanche 4.0L. Since Chrysler reversed the polarity AND changed the resistance levels and range when they went from Renix to HO, it's impossible for the same unit to fit both years. It's probably an HO unit.

 

It's possible that a gauge out of an HO cluster would fix it. But ... they might have used the same gauge and changed the polarity by using a different printed circuit board on the cluster. As a last resort, you could cut the traces on the circuit board and use wires to connect the gauge, but once you cut the printed circuit there's no going back.

 

One other way would be to pull the main connector off the back of the cluster. Identify the two wires that feed the fuel gauge, pull them out of connector, and reverse their positions.

[HOrnbrod]

15 hours ago, Wounded_Fighter said:

So... could it be re-reversed? lol

 

Maybe, but I know nothing about how the Chinese aftermarket sender you are using is constructed, but this works for the Mopar senders The sender float follows the tank fuel level up and down, and acts as the slider of a variable resister called a potentiometer. To reverse the voltage output polarity to the fuel gauge, you will need to unsolder the potentiometer output wire and resolder it to the other side end the potentiometer, so the fuel gauge senses the ohm output going in the opposite direction that it is now, i.e. hight-to-low to low-to-high. Then your gauge will increase when the float rises, and decrease when it goes down. Wether it's accurate or not, ???