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Legolas894 · 07-26-2009, 10:58 PM

One check I did today. I put an ohm-meter on the sending unit in the tank with the gauge wire off. It read about 57 ohms. I added some fuel to the tank, the ohms went up to about 60. Therefore, sending unit is OK I assume since when empty it should go to 0 OHMs which is basically the same as grounding the gauge wire.

Higher ohms reading = more fuel.

I also happen to have a 0-100 ohm variable resistor from another hobby. I put this on in place of the sending unit and the gauge would only move if I moved the resistor to 0 ohms. 90ohms should have made the gauge read full but it stayed at the way-past-full the whole time until 0 ohms.

There's a few gauges on ebay and a new one is only around 40 bucks.

I must have a gauge problem.

07-26-2009, 10:58 PM	#12
Legolas894 Chemist under the hood... Join Date: Apr 2009 Location: Fort Erie,ON, Canada Posts: 617	Re: Fuel gauge problem One check I did today. I put an ohm-meter on the sending unit in the tank with the gauge wire off. It read about 57 ohms. I added some fuel to the tank, the ohms went up to about 60. Therefore, sending unit is OK I assume since when empty it should go to 0 OHMs which is basically the same as grounding the gauge wire. Higher ohms reading = more fuel. I also happen to have a 0-100 ohm variable resistor from another hobby. I put this on in place of the sending unit and the gauge would only move if I moved the resistor to 0 ohms. 90ohms should have made the gauge read full but it stayed at the way-past-full the whole time until 0 ohms. There's a few gauges on ebay and a new one is only around 40 bucks. I must have a gauge problem. __________________ Current fleet: 2013 GMC Sierra, 5.3L, 4x4 1988 GMC Sierra, 305, Auto 1984 Jeep Grand Wagoneer, 360 V8 1997 VW Cabrio, 2.0L 2017 Toyota Rav4, 2.5L Stuff I wish I still had: 2013 Toyota Matrix [RIP] 1967 GMC 910 Fleetside, 283 V8 [1st Love-SOLD] 1987 Jeep Cherokee Laredo 4X4, 4.0 I-6 [SOLD} 1994 Chevrolet Caprice Classic, 5.7LV8 [SOLD] 1995 Chevrolet Astro AWD, 4.3L V6 (RIP) 1998 Chevrolet Suburban 4x4, 5.7L V8 [SOLD]