dougdb332

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dougdb332

Ok so I replaced the gas/temp gauge because it was reading full. The new gauge dropped to empty. So I replaced the sending unit. The gauge worked. But would flucuate slightly. I assumed it was a low quailty sending unit. But after swapping the unit I wanted to see if the gauge was even faulty after all. (I didn't have a multimeter at the time, just recently got one and am still getting use to it) when I put the old gauge back in, sure enough it floated back to the top. So I took it out and put back my new gauge. But when I turned my car on it floated to the top too. Now I did keep the old Part that goes on behind it that let's you know what gear your in cos I noticed on my new gauge it sometimes wouldn't light up. Could that be the faulty part since it is what the harness connects too? Anyways I immediatly put the new one back in again. But it's still reading full. I even tried disconnecting the sending unit and the needle stayed. I read in a forum that it could be because I could have screwed those 6 screws in too tight. Is that a thing? Any ideas would be appreciated thanks guys

mk378

With sending unit unplugged, gauge should go to empty when you turn the key on. The sending unit wire shorting to ground will cause it to read full when it is not. This can be checked by unplugging the cluster and measuring ohms from that wire to ground. It should be in the range of 10 to 40 ohms depending on how full the tank is, and go to open circuit when the sending unit is unplugged at the tank.

Also check your cluster ground. Does everything else on the cluster work OK, the temperature gauge, tach, speedometer, warning lights?

There will be some fluctuation while driving because the gas moves around in the tank. For example, going uphill makes the gas move to the back, and since the sending unit is in the front it will read lower.

dougdb332

I have unplugged the sending unit and turned the car on and it remains at full. But I don't think that is the problem because the needle rose to full before I even touched the sending unit. This occurred while the car was parked, and while I was only messing with the cluster. One minute the gas gauge worked. I swapped it out with my old one. And the needle rose to fill again. I put the new gauge back in and all of the sudden it started doing the same thing. All of the other gauges and warning lights work. Also I would like to mention that on the old fuel temp gauge the temp side works too. It's only the fuel side on bother gauges that doesn't work and the whole cluster works fine too. When I get home I will test the wires but I'm still getting the hang of my multimeter and I'm not sure where to put the prongs exatly. The connecter that connects to the fuel/temp part of the gauge has so many wires.