Rexall fuel gauge

[Orion]

I've been an RV'er for a long time but never a motorhome. An old widow friend is fixing up her MH before selling it. The only thing left is the fuel gauge, tank is full but gauge shows empty. Is there a way to tell if it is either the tank sending unit or the gauge itself. Thanks!

[Orion]

I really don't know what chassis this is mounted on, other than it is a 460 Ford. I did read that on most class A's the tank has to be dropped to get at the sending unit, but I have also seen mention of them being accessible via the floor or hidden panels in the compartments. I'm hoping that even if the unit is at the top of the tank, where it grounds may be accessible as this can be the culprit.

[ernie1]

You haven't mentioned what the chassis make is. I had the same problem with my 1989 E350 Ford. The problem was a leaking brass float attached to the end of the arm of the sending unit. Bought a new float for $10 and everything was good afterward.

[Roger10378]

The sending unit is always on top of the tank to lessen the chances of a leak. Unfortunately that means in most cases the tank has to be dropped to get to it. You will need to remove most of the fuel as the tank is very heavy when full.

[Orion]

We eventually figured out to check which wire from the tank and crawled under there this morning. Where is the sending unit, went all the way around it and could see nothing. Is it on top of the tank? We went under the bed and all there is there is the water tank and a solid floor with no access panels. Do you have drop the tank to get at the sending unit?Thanks!

[Orion]

Thanks for your help(s) ! I cant get under the tank to look at it , so we'll have to get her son to get under there. How many wires go to the sending unit, two or three?

[Microlite_Mike]

RLS7201 wrote:
Apply ground to the wire from the sending unit. Either at the gauge or the sending unit. If the gauge moves, you need a new sending unit, or have an open connection between the two.

Richard

I would think "simple" first. The wire from tank sending unit to gauge is long and often exposed to all kinds of perils.

Check to see if it's cut or broken along the frame between tank and dash. Can't count the number of times I've seen a wire hanging down from the bottom of a vehicle with this problem and guess what, it went to the tank sender:C

[RLS7201]

Apply ground to the wire from the sending unit. Either at the gauge or the sending unit. If the gauge moves, you need a new sending unit, or have an open connection between the two.

Richard

[jdc1]

https://www.delphiautoparts.com/usa/en-US/resource-center/whats-wrong-my-fuel-gauge-diagnosing-bad-fuel-sending-unit