Fuel gauge problem still!

[Diego Zuniga]

This is my last electrical issue then I am hopping to just enjoy my 521. So here is the deal, my fuel gauge stop working a month ago it would read e when truck was off then go to f when key was on. I ran all the test you guys recommend with no result. So while fixing another electrical issue I found 2 broke wires in my harness under the truck going to the back. A red and blue wire then a black and white wire.I connected them back together and now my gauge stays on e even when truck is running. So I ran my test light to the yellow wire from the gas tank and my test light is only half the brightness it usually is and its flashing when the key is on. I even checked the yellow wire where it plugs into the harness at the firewall and have the same result there.

[DanielC]

Take the yellow wire off the fuel level sender on the gas tank.  Ground it.  Does the gauge go to full, with the key on?

[Diego Zuniga]

I put the yellow wire to ground and turn the key on and yes the gauge moved up.

[datzenmike]

Now re-connect the Yellow.

 

Ground the Black or other wire to something solid like the frame.

 

Does the gauge read properly?

 

NO gauge does not read..... the sender is defective or the float is stuck in the down position or sunk to the bottom

 

YES gauge now reads something.... your ground wirewas not properly grounded.

[Diego Zuniga]

Thanks so much for all your help I truly appreciate it. The sending unit was stuck. I taped on the tank with a hammer and it came unstuck. I hope its stays working. Thanks again for all your help and sharing your knowledge with all of us