pickup fuel gauge

[HighRaven]

have an 89 pickup . but the gas gauge doesnt seem to work. I've checked the fuse box and made sure it actually had gas in it . any suggestions for things to check would be great.

[MenaceSQL]

It could be the sending unit. My sending unit crapped out once in my '89 truck.

[HighRaven]

is there any way to test the sending unit

[fredk]

sure, pop it out of the tank and hook the wires to it, now turn the key on and raise and lower the float and watch the gage

[PatchworkYota]

I'm not sure what the correct range is, but the sending unit is basically a float at the end of a wire attached to a potentiometer. It's located further back on the gas tank than the fuel pump housing. There should be resistance across the leads coming from it. (or between the wire and ground) If it is a dead short, or shows no connection (more likely), the sender is your problem. I've never had mine out, but I used to work for a fuel sender manufacturer. You may be able to service it yourself when you remove it. If it's accessible, you may ony need to clean the contacts that the float arm swings past. The floats sometimes develop cracks and become filled with gas, therefore not floating anymore. If you do remove it, soak down the bolts ahead of time with some pb blaster or wd40. I had a bolt break on me when replacing my fuel pump.