Gauge stopped working a while back. Is there a quick way to check if its the sending unit or the gauge? I thought at one time I checked a different sending unit by removing it from the tank, moving the arm back and forth, and checking it with an volt meter, but i don't remember. Is there a way to check the gauge to make sure if it working correctly? It registered below empty now. Also, if I need a sending unit, where is the best place to buy one? I think most are aftermarket, and I would like to buy the best possible one available. Thanks!

 

You can turn the key to accessory, then crawl under the truck, disconnect the wire going to the sending unit, and then ground the side coming from the truck's wiring harness. If all the wiring is good, then the gauge should peg to FULL. If that's the case, then the sending unit is bad. Most often times, in this case, it's because the float punctured, and sunk to the bottom of the tank, permanently reading EMPTY.

If it doesn't peg to FULL, then the wiring is bad. Most often times, it's because the crossmember where the sending unit grounds doesn't have a very good connection with true ground. If your tail lights still work, then you can try running a jumper wire from where the sending unit grounds, up to the bed sheetmetal - this usually gives you a clean, easy-to-access ground point.

I bought a sending unit from Jeff's Bronco Graveyard, and it died in less than a week. Based on the behavior, it looked like the float punctured due to poor soldering joints on the float. I don't know if it was a one-time thing with them or what; it was too much of a pain to pull the tank again and fix it a second time. Since then I've been writing the mileage of the last time I filled up on the dash with chalk, and I just go by that. Too many other projects going on. Find the highest quality sending unit you can; maybe others have some good recommendations (I would be curious too).

 

Pull the connector at the sending unit and ground it. The gauge should peg.

That's a nice fuel tank selector switch ya got there...

 

What said above to troubleshoot. Floats are available from various places.

 

If you replace the float make sure it is ethanol proof. Some of these new replacement non-bulb type floats are being eaten up by the ethanol.

You are probably going to think that I am bs’ing you but I pulled a sending unit out of a tank once and someone had taken a small appliance type light bulb and attached it to the sending unit as the float. It was sure MM, but I guess it worked.

 

thats freakin awesome.....

 

ok, got up to look at my truck and the reason the fuel gauge probably does not work,is because the wiring that is suppose to go to the sending unit is gone. I have nothing hooked up. I guess I need to figure out where under the dash this comes from and see if its tucked up there somewhere. I looked but didn't see much more than a 2 prong plug and nothing on the end. Anybody give me ideas? thanks

 

My gas gauge doesnt work as well. When I turn the key on it pegs to full, so is the sending unit bad?....Thanks

 

If the gauge pegs to full then the wire going to the sender has grounded somewhere between the dash and the tank. Go under the truck and unplug the wire at the tank sender. Recheck the gauge. If it acts the same look for where the wire has grounded. If it doesn't move replace the sender.

 

Ahhhh yes those little grounded out wires...I had to replace a torque convertor and I got part of the wiring harness pinched under the back transmission mount.