Our 99 trooper just had a gas tank installed, and now the gas gauge doesn't work. They tried another sending unit.

see the diagram attached and fix it. God bless you

Power should goto the gauge, second wire from the gauge goes to the sender unit on the tank. If there's any other terminals on the gauge or the tank they will be grounds

It may be the sending unit in the tank that needs replacing. Here's how you can check: Turn the key on and disconnect the sender unit at the gas tank. Ground the sender unit's wire with a jumper wire from the truck's harness to ground. Watch the gauge. If the gauge on the dash is good, grounding the sender wire will cause the gauge needle to react and should move to full. This would indicate a new sending unit is required. If the gauge doesn't move when the sender unit is grounded, the gauge is bad and needs replacing. Pull the instrument cluster out to replace the gas gauge. Likely any old ford gas gauge might work-back then, there were not so many production changes.

There is no fuse specific to the fuel gauge. The Instrument panel has two fuses that supply power to everything it has on it. The fuel gauge signal is received from the body control module which sends out a signal voltage to the fuel level sending unit. Depending on where the float in the tank in determines how much resistance the sending unit has. the body control module interprets the voltage value into a fuel level and sends a signal to the gauge.

If the gauge is not working the most common cause is the sending unit in the tank.

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Sending unit in gas tank or bad ground

you have a bad sending unit ,its inside the fuel tank,you have too drop the tank too replace it!!

HI, the gas gauge sending unit is located inside the fuel tank. it is part of the fuel pump assembly. you will need to lower the tank to access this sending unit. replacing the sending unit will fix this issue.

I have the same problem on my 99 ZR2 Blazer. This is the rheostat in the gas tank. I bought my part in Ebay for $27. The only issue is that you have to drop the gas tank and pull the sending unit to install. Hope this helps, I hear from other message boards that it is a very common problem in these vehicles.

The only thing that will cause this is the gas guage sending unit.

your sending unit in the gas tank is bad. You most likely already priced a new one that you can only get with a fuel pump. {around 275-300 dolllars}. I found the sending unit by itself on ebay for around 40 dollars. Just go to ebay and type in 98 99 00 01 02 rodeo passport fuel sending unit and that should take you to the guy I'm getting mine from.