I have a 90 E250 van that is supposed to have a 22 gallon tank. My guage goes to full when I fill up and linerly goes down to empty but I've only used 10 gallons. Is this always the sending unit gone bad? Is there anything I could do sending unit, ie. clean contacts, that might help? The guage shows full range, just not for what should be in the tank.

 

Take the wire off the sending unit, and with the key on, ground the wire to a good ground, and then take the wire off the ground and let it touch nothing. Everytime you do this, the gauge should swing back and forth full scale. If this works, that tells you the wiring and the gauge are good.

You can then pull the sending unit out. Check to make sure the float does not have fuel inside it. Also eyeball the movement of the float, and the height of the complete unit, and see if it jives with the tank you have. You never know, someone may have mixed up some parts if you bought the van used.

 

And they work backwards. Shorting it to ground gives you a Full reading. Not connected should jam it on Empty. They work around 0-70 ohms inversly.


You've got the classic junk fuel level sensors Ford used during many of those years.

I've never worried about replacing any of mine and just went by fuel mileage. I was told you have to replace the whole in-tank assy. so I never worried about it.

 

[QUOTE=2000Ford2000]And they work backwards. Shorting it to ground gives you a Full reading. Not connected should jam it on Empty. They work around 0-70 ohms inversly.QUOTE]

I stopped designating which way they went, because Ford changed the direction sometime in the late 80's or early 90's. So it's easier for me to say full scale one way, and full scale the other way.

 

I know that the 90 works that way for sure, but I don't know when they changed. I thought that Chevy worked 'normal' and that Fords worked inverse but since I haven't had all of those years of vehicles, I don't know.

If Ford really cared about us, they should have recalled all those bad sensors. Never had a GM or Chrysler tank gauge go bad, but I've sure had a lot of Ford ones go out. My 2000 E-150 gas gauge is flaky too but over time, it settles down. Whenever I put gas in it, it takes 10 mins. or so before it shows a correct reading. Even my old 82 Merc Capri had a sensor problem somewhere as the LED that came on to tell me the gas was low, came on at 3/4 tank, even though the gauge read correct.

Funny that I had 2 89 E-150's that came off the line 11 vans apart from each other. On one, both sensors went bad in the twin tanks and on the other, they are both still OK. The first also blew a head gasket, 2 brake lines, a steering box and both gas tanks rusted out. I treated both vans the same as far as driving, service, and everything else. The only thing I can figure is that there must have been a shift change between the 2 at the factory.

I miss my 71 Pinto. That gauge worked all throughout its 250,000 miles. Can't say that for the rest of it though.

 

You sure it's 22 gal.? I've seen twins with 15 and 17 and singles that are 36 but not a 22 after 1985. The owners manual says for sure what you've got.

If you don't have it, carry some gas with you and run it dry. Then you'll know. If you're like me, I usually run out at a stoplight, but have been able to pump it enough to get it off the road.

I just about screwed up last year in my E-350 26' RV. I must have had a big headwind as I thought that I had several gallons left in the tank (Gauge sensor bad, of course). I had just pulled off of I-70 in Effingham, IL and was headed for the Flying J. I stopped at the light at the end of the exit lane and when it went green, I had no power. I was able to idle it across the road and up to the Flying J pumps before it died. In the summer I just fill it when the generator dies (run it for the overhead A/C) as it has 10 gallons left at that point. At 6 mpg you'd think that Ford would put a tank larger than 36 gals. in it. Stopping every 2 hours for gas sucks. There is a 49 gal. tank that will replace it, but at $640, it ain't worth it. I'm about ready to convert it to LP. I think there's enough room under the back for tanks to give me a 1000 mile range, but I have to make sure it doesn't overload the rear axle as the RV is about maxed out as it is. Or maybe I'll just sell it.

 

My bad. Called my van mentor, my uncle, and he said there is a 22 gallon for your van.

 

I thought about the carrying a gas can thing, but I too always run out at a light in traffic, and I'm too old to remember how many miles I've gone on that tank. Funny thing is the guage seems to be working correctly now. Thanks for you help guys.