My truck fuel readings have been getting worse over time. First it was reading high then would read good. After that I noticed on highway trips the faster I went the higher the fuel read, now it just lingers at full most of the time and only goes to 3/4 if it is getting close to empty. (I know this by keeping track of mileage and fuel comsumption) I adverage about 16 mpg around town. But I have gotten tired of counting miles and coming close to running out of gas when I forget the guage is dead wrong.
Has anyone ever had the misfortune to have to change this unit? I have tested mine at the canon plug at the tank ( from the sending unit side). I was suppose to get readings, on a 200-ohm scale meter between 160.0 (fulltank) to 15.0 empty tank. I calculated my tank at about 8 gallons +- but only had a reading of -1 (read it 5 times).
I checked around and found that Ford was where I have to get the part, and it is now only sold as a complete assembly, (so I was told) 300+hard dollars.
I have heard that it is a real pain to change out and some have said it is easier to pull the bed to do this. Well with lots of new paint and low on manpower I think the bed is staying on. So I will have to go at it from under the truck. Does anyone have some past experience advice before I jump into this task?

 

If you have to do it on the ground I would say pulling the bed would be your best choice. You will need several buddies to help you lift it off.

 

Well that was a job that I don't want to do again any time soon. It wasn't as bad as I thought though. Used a hydralic floor jack, 6x6x12 wood block and took it slow. The hardest thing was getting the two main fuel lines & locks off blind. (8am to 3pm)
The bad thing now is that the truck is doing what it did a year or so ago. The fuel guage is reading high (1/3 full) with 4 gallons in the tank and the oil pressure guage reading low and sometimes going to zero or bouncing then back to normal. I Thought that problem was a fluke back then. Having near heart failure the first time, when the oil pressure went to zero, instantly shutting down and checking everything. I know there is nothing wrong with the oil pump and system. So I guess I will be going to the guages for answers. I have never run across two guages acting up together. I am also hoping that the sending unit problem was a seperate problem and wasn't caused by this original problem.
Any ideas or someone have this happen too?
I think I may see if I can track down a whole instrument panel and swap the whole thing out. Either way I have to rip the dash apart.
I should of started my "quit smoking program" after all this was done instead of before.

 

I would try an oil sender first, its cheap and may fix the oil guage problem. Ive had to replace a lot of them on late model trucks.

Wait on the fuel guage for a while and see how far off it is after running a full tank or so through. It could be a slosh module problem which comes with the gauge should you decide to replace it. You dont have to tear the whole dash apart, just remove a few pieces to get the cluster out. You can remove the cluster and swap the guage and slosh module in about an hour and a half.

 

Myself I am use to 76 and older model Fords since that is what we have the most of, so I will clear up when I say tear the dash apart, pulling more than one panel is like tearing the dash out to me. lol
I see what your saying about the oil guage, the only problem is I never had this problem except when the gas guage first started to act strange.Any other time over the past year the oil guage has been right on the money. Tonight I noticed that it goes plumb dead to zero (oil guage) in a sharp turn, tap the dash and it pops back up. The gas guage has not moved for the past 50 miles from plumb full. When I put gas in (empty tank) after reinstalling it I put in 4 gallons (read empty then one third) then 21 gallons at the station it went to full. I forgot to mention that when this stuff all started a year ago that the gas guage would read fuller the faster you went and back to normal reading at idle (if you went by the trip meter counting miles to gallons).
I have been reading some wiring diagrams and it shows some solid state blocks that the guages seem to run into behind the dash (?) So tomorrow I will be chasing and testing wires,guages and looking for these blocks(?)canon plugs. As far as the sloshing, the gas gauage never moves, in hard corners, hard braking or hills.
I figure that the problem has to be something buried just enough to be a pain in the neck to get to. Ain't' it always the case. I will keep you posted on what I find. Thanks for the input and I will be checking that stuff too. I have noticed a little improvement in the acceleration, so maybe the fuel pump was getting a little tired? It was original to the truck or..... I just want to belive it to feel better about what the thing cost.Ha!