Fuel gauge not working.
 

In my 1974 F250 4x4 (highboy) the fuel gauge is not working. I replaced the sending unit and nothing. I checked to see if there is power when the ignition is switched on and acc and there is. What else could be the problem? Any thoughts?

do you have dual tanks?

I was having trouble with all the gauges on my 75 when I first bought it. Spent days chasing wires and reviewing schematics... The root of my issues boiled down to the schematics not necessarily being 100% accurate.

The trouble as it turned out was with the ground. I am not the best person to explain this but basically instrument clusters work off the ground versus the power. And there are two grounds, a general and one with the resistance wire; once I determined where each was and where they went the cluster lit up lit a xmas tree.

I even went so far as to replace the entire cluster but the same issues were present; I later found out that the clusters don't often go out. Its usually the wiring going to the cluster that has the issues.

Disconect the wire that goes to the sending unit and ground it. If the gauge goes to full then the problem is either the new sending unit or the ground. If the gauge still reads empty with the wire grounded, the problem is either the gauge itself or the wiring.

Okay, I took the wire on the top of the sending unit and "grounded" it. I held it one of the bolts that holds the sending unit in place on the tank and after some sparks and smoke, the gauge never moved. The orange wire got very hot as I held it to ground it out. Do I need to remove the actual ground wire to conduct the test or leave it there? I left it in its place and like I said the main wire to the sending unit got very hot and the gauge never moved.

If the gauge is bad, who makes replacement gauges?

I had to pull my gauge cluster out of mine and clean the copper circuit board up with some fine sandpaper. take the piece off that is for the gas gauge, clean it and under it..go all around the whole circuit board, taking every bulb out and cleaning around it, along with takin off the little nuts and cleaning under them as well.

I did clean the copper for all the lights, but no the gauges. I'll try that. Give me about 30 min.

Here's 22 of the puppies NOS (New Old Stock).

D3TZ-9280-A .. Instrument Cluster Fuel Gauge-Use with Leaded Fuel / Obsolete

Applications: 1973/74 F100/350 / 1975/76 & 1977 F150/350 before serial number O80,001 / 1975/76 & 1977 Econoline before serial number O80,001.

ANTIQUE AUTO SUPPLY in Arlington TX has ONE = 817-275-2381.

ERICSON FORD in Loup City NE has ONE = 308-745-0667.

TISON MOTOR CO. in Estill SC has ONE = 803-625-2551.

PARTS INTERNATIONAL in Farmers Branch TX has FOUR = 888-727-0418.

KINSEL L/M in Beaumont TX has FOUR = 800-816-2894.

CARPENTER NOS OBSOLETE PARTS in Concord NC has FIVE = 800-476-9653.

GREEN SALES CO. in Cincinnati OH has SIX = 800-543-4959.

Be sure to check your resistor wire for breaks or disconnects. Also be careful arcing on a fuel tank.

ok............

I saw a setup which replaced the entire cluster and trim all the way over to the climate control and radio with a piece of aluminum with cutouts for the accessories; the gauges were all aftermarket... Autometer I believe. If I wasnt trying to stay closer to the original look i would do this. It was really nice and clean plus durable.

The resister wire is the "hot" wire or in my case the orange wire, right?

@ NumberDummy. Nobody has anymore gauges or there are 22 available?

I cleaned the contact area for the gauge on the back of the cluster and still no movement.