Topic: fuel gauge go to infinity when key turned on

[ta78w72]

You have to connect both leads to the ohm meter.  It should show no resistance.  That would indicate no breaks in the wire.  If it shows infinite resistance, you have a bad wire.

If it tests good, it's the gauge.  You may have two bad gauges, but to really figure it out, I usually pull the gauges and test them on my workbench.

[medicman]

Just a quick update, getting ready to test the fuel gauge but first I thought I would put the gauge cluster back in and guess what and it did the same problem as before. Felt my eyes starting to cross again, lol.

I took it out and plug it back in and it was fine, at this point I am thinking what the #@%*& is going on!!

Keeping patience, I started the very technical process of jiggling wires! Low and behold, I found that the plug to the cluster was the problem. If I pushed it to the left it would be fine, as soon as I let it go, the problems came back. I bent all the little connectors on the plug out a ittle and all is good. So that problem is totally fixed.

Now onto the fuel unit. I will start with the first test with ohms in the trunk and let you guys know what happens

[medicman]

tested the wires at the trunk, a few inches above where the wire goes into the rear panel and I got 3.6 ohms? So that is not zero but not infinity.

[medicman]

OOPS!! I read your instructions wrong. So here is what I did, I unplugged the 5 pin harness in trunk, and then ran a wire from the fuel gauge to the trunk and tested the ohms. My meter read "o.l" I guess that means open line. I am guessing I have a break somewhere between the trunk harness and the gauge.

Let me know if I did this test correctly. I think I did.

Thanks.

[ta78w72]

No, the sender wire comes up from the tank through the bottom of the trunk near the latch.  You should be able to see the connector.

[medicman]

I fixed the gauge. What I did was unplug the 5 pin harness in the trunk and grounded out the feed wire to the gauge. The fuel gauge went to empty. I cleaned the ground coming off the gas tank and it did the same thing.

I dropped the gas tank and pulled the sending unit out. I noticed a black wire going down to the sending unit and it looked extremely dirty. I cleaned it up and tested the float and it worked perfectly. I guess it the black wire just needed cleaning up.

Thanks for all the help,

All my wiring issues are over!!!! Everything is working great. Now I can start reinstalling my interior.