Hi- I have a 74 F350 reg. cab Super Camper Special w/460 and C6. I decided to remove my midship (auxiliary) gas tank today to clean it out. I am going to be installing a new carb soon and wanted to make sure the tanks are clean before doing so. I was shocked to see how clean the inside of the tank was and the gas in it was extremely clean. I cleaned it out and replaced the rubber fuel lines. The fuel gauge used to work intermittently on the auxiliary but always worked on the main. Just recently the fuel gauge stopped working on both. I removed the fuel sending unit and it looks greats and appears functional. The float appears good, connecting wire is intact, but no sock. The outside connector to the sending unit appears to be in good shape too and not corroded. Any ideas of what I should look for to see why the fuel gauge no longer work? Thanks for your help.

 

Ground the wire that goes to the fuel sender, turn the ignition to the "run" position. The needle should swing all the way to "full". If it does then either the sending unit is bad or the sender's ground connection is bad.

EDIT:
DUHH!, The way I wrote that it sounds like you ground the wire on the pigtail that plugs into the sending unit, you don't. What I meant to say was to ground the wire that comes from the gauge, where it plugs into the pigtail.

 

Something here might help you...

Fuel Tank Sending Unit Tech - FORDification.com

or this

https://www.ford-trucks.com/forums/9...ding-unit.html

or this

https://www.ford-trucks.com/forums/9...cs-needed.html

 

Hey Mike and Kikkup, thanks for the information and resources. Exactly what I was looking for. I'll start my troubleshooting efforts this weekend.

Thanks,