Fuel Gauge reads backwards?

[Kafka]

I think I have a gremlin in my wiring harness.

In doing my current rebuild of my '79 CJ7 , I replaced all the gauges with Stewart Warner Wings gauges. I have all of them working, except the fuel gauge which is causing me fits. It is a 90-0 ohm gauge, which I know is different than the OEM sending unit so it will never read accurately, However it is reading backwards: Full when empty and empty when full. I have messed with all the wires, re ground everything, and still cannot figure this one out.

Of note, I installed a Painless Wiring universal CJ harness, and am wondering if that is the culprit, as I have found several errors in their wiring diagrams.

Thanks,
jim

 

[Posi]

I have all of them working, except the fuel gauge which is causing me fits. It is a 90-0 ohm gauge,

Jim, double check your gauge, I believe some Stewart Warner Wings fuel gauges are 0-90 ohm which would explain the gauge reading backwards. Jeep sending unit is 73-10

 

[gutthans]

Jim, double check your gauge, I believe some Stewart Warner Wings fuel gauges are 0-90 ohm which would explain the gauge reading backwards. Jeep sending unit is 73-10

Yes, SW gauges read backwards...IIRC there may be a SW guage that reads 'forwards' But VDO does read the proper direction.

 

[mtnwhlr]

If it has two wires at the guage have tried switching them? I know that may be to easy

 

[Posi]

If there are 2 wires I would caution against switching them. At this point the sending unit works, switching could possibly send 12v straight to the sending unit and frying it.

 

[Kafka]

Thanks. I thought the fuel gauge read the ohms differently. I am going to see if I can retrofit a S-W sending unit, so maybe I can get the correct reading.

Thanks for the help, this one has been bugging me.

jim

 

[Posi]

If you purchased new you should be able to exchange it for the correct SW 82495 or 82342 gauge.

White face
http://www.summitracing.com/parts/sww-82495/overview/

Black face
http://www.summitracing.com/parts/sww-82342/overview/

 

[sketchy]

E = Enough, F = Fill it up?

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