GET A NEW MECHANIC! That guy is taking you to the bank! Did you get a brand new motor in it for 2200? He sounds like a idiot to boot! You can order a new sending unit from many chain parts stores and reproduction places like JBG, Dennis Carpenter, LMC, NPD.

Get a Chilton or Hanes basic maint manual for that series of truck and learn to fix it your self. Dropping a tank it not that bad, neither is trouble shooting it.

Ck out and join up your California FTE chapter and get some local help.

 

Fuel sender
76-up F100-350 >s/n C00,000
Use with aft axle steel tank, includes gasket
D7TZ-9275-D
Bob Hoover Ford-Mercury, Vienna, IL (618) 658-9218
Brighton Ford, Brighton, MI (800) 336-3305
Beau Townsend Ford, Vandalia, OH (937) 898-5841
Own Ford, Jarratt, VA (434) 535-8515
Vintage Fords, Beaver Dam, WI (877) 846-8243

Disconnect the wire that goes to the fuel sending unit at the tank. Ground that wire to the frame, making sure the frame is clean. Turn the ignition to the "run" position and watch the fuel gauge. If the gauge swings all the way to full, either the sending unit itself is bad or it has a bad ground. If the gauge stays on empty then either the gauge is bad or there is a wiring problem.

To pop the plug off for the test, you can barely get up in there with your head and see the plug. While looking at it, VERY CAREFULLY use a screwdriver to pry it off. AND I MEAN VERY CAREFULLY. It is only pushed on like a 1/8". This is only if you can’t get it with your hands.
Once you have done the test (above) and decide it’s the sending unit. And you have cleaned the ground and that did not work. Then disconnect the ground again and fuel line and read on….

If you can't get either one disconnected, no worries you will have a little more room once the tank is dropped down a little. But make sure you have some wire slack in the plug connector.
Run the tank dry or almost or siphon it empty, I would not do it with ½ a tank of fuel, but if you just have to, just use a big floor jack and a piece of 2x2 plywood. It’s not heavy at all, unless you have it full or 1/2 full of gas. DRAIN THE TANK!
Loosen the filler and vent hose clamps at the tank end and maybe you can pop the lines off? But most of the time you have to just loosen the clamps and wait till the tank is about out.
With the jack in place, or not, just loosen the hdwr (2 bolts) on the front straps, and remove the tank straps aft hdwr all together, then swing the straps out of your way.
Slide the tank to the dvrs side about 1/2" and then pull out or let the passenger side come out of the frame. Then disconnect the elec connector and eng feed fuel line if you could not get to them earlier.
Then slide it as far as you can to the right and pop off the filler/vent lines. Sometime you need to carefully put a flat tip screwdriver in between the rubber hose and the tank to break it loose. The filler neck and vent lines get stuck to the metal pretty good sometimes.
Once the tank is removed there is a lock ring that comes off with a screwdriver or punch, look for a small tab that has been bent over to lock it. Un-bend it, tap off the lock ring, remove the sending unit.
Insp the underside of the tank where the support straps rest, lots of dirt and moisture build up there, and that causes the bottom side corners to rust out. You can also come reinstall time replace the anti-chaff material. Old 2" ratchet strap work great, glued to the support straps.
Insp the inside of the tank, might be a great time to replace it all together? Before you reinstall anything connect the electric connection and ground to the sending unit. Wire it up under the truck so it is not hanging by the connection. And with the key in the 1st (on position) you should be able to move the float arm and see a difference in your gauge?? It is always easier to do this with a helper.....
Also before install, paint the complete tank with some good paint. Even spray on bed liner or undercoating??

 

Thanks for the info. No, this mechanic didn't put in a new engine but for the price he charged me, he should have. Knowing that it is fixable, makes it better. I'm a women and not experienced in any sort of mechanics but I can take it back to the mechanic, says truck work is warranted for 2 years. Thanks for your time!

 

X2 on yes for that amount of $$ you should have NO ISSUES AND A WORKING GAS GAUGE! You really need to find a mech that is not ripping you off and BS'ing you on your fuel tank issue.

Get on the FTE California chapter, north or south and ask for some in state advice on a good mechanic or shop in your area.

 

You are so right! Thank you so much.

 

What part of CA ya located in???

 

We are located in Roseville Ca, near Sacramento.

 

Had a similar problem as Fordrun, with a '74 a few years back. Fortunately for me, no one had tried to "improve" the factory wiring.

The problem ended up being corroded contacts on the dash "tank" selector switch. The switch actually only switches the sending units to the gauge, the tanks are switched by the floor mounted valve.
I removed the switch to access the wiring, and proved out the wiring to both tanks and gauge as well as the two sending units and the gauge.
Once I identified the switch as the problem I applied a little WD-40 and worked the switch 300-400 times, flushing with WD-40 every 50-75 operations of the switch.

Hope this helps.

 

Awesome! Thanks for the info!