Fuel gage, what kind to get?

[crasster]

I have 2 fuel tanks on my Dolphin, and the main fuel tank for driving has a malfunctioning gauge (I have not tested the genny gauge with enough gas yet). This is an "installed" tank that is in the back. I estimate it to be between 20-30 gallons.

This tank is read on a separate fuel gauge installed under the driver's console.

So anyway, the gauge is not working. It was reading "Empty". So I went in the back, and cleaned off the terminals. Still read "empty". I took a jumper wire from the wire with the boot on it, and grounded it, then the gauge went ALL THE WAY up, I mean way past full. Once released, the gauge went back to empty.

When I power off the vehicle, the gauge drops below empty, and on power on, the gauge goes up to empty.

Anyhow, I take it this is either:

1) A bad sending unit

or

2) A bad float that is cracked or sinking etc.

I have NO idea what brand or model of tank this is.

My question are;

1) Are fuel sending units pretty universal? If not, will there be identifying markers on the sending unit?

2) Is there anything else I want to change while in the tank? I would guess a fuel filter since the system will be emptied of gas?

Thanks!

[Rolling TMCI]

I have the same problem with my 86 dolphin, but the gauge is in the dash, and yes I have narrowed it down to the sending unit. The sending unit is whatever the chassis is, for example my chassis is an 86 Toyota pickup with a 22 rec motor. Now granted this is not an easy task to drop the tank and replace the unit, so while it is down you should clean or replace the screen on the fuel pump. A good source for the unit is jcWhitney.com, or a junk yard. I have not installed my unit yet, cause of snow and no garage, but I am very anxious to get it installed, have a big trip planned for March.