Inoperative Fuel Gauge

[Fanch00]

Hello everyone,

The fuel gauge on my BT7 is not working. I have to monitor the mileage to know when to refill, at the risk of getting it wrong and running out of gas.

I have limited technical knowledge but am keen to try to fix it. Where should I start?

 

[Madflyer]

First does it read any fuel. ?? and does it move at any point? most time the float goes bad with todays gas and sinks. Also any moisture can rust the pivot sticking it at a fixed point. The gauge works by reading ohm to ground and is rarely the problem. Getting acc. to tank and replacing float assy. is most likely the fix.

 

[BobHaskell]

The mgaguru.com website has quite a bit of technical info. Here's a article on troubleshooting the fuel gauge/sending unit.

 

[BoyRacer]

My fuel gage is usually correct. Except for that time I ran out of gas but the gage read one-quarter tank. I keep a wooden dowel in the trunk to use in those times when the gage reads low or when I have that "feeling". And, it confirmed I was out of gas that time that the gage say 1/4 full.

 

[Fanch00]

First does it read any fuel. ?? and does it move at any point? most time the float goes bad with todays gas and sinks. Also any moisture can rust the pivot sticking it at a fixed point. The gauge works by reading ohm to ground and is rarely the problem. Getting acc. to tank and replacing float assy. is most likely the fix.

The needle doesn’t move at all. Like, the gauge is dead. thank you for your advice, I will look into the tank first and check the float. Where’s the float connected to the gauge? I may as well check the wiring.

 

[Madflyer]

They all look something like this

 

[roscoe]

Was it working and then stopped abruptly? Did it ever work for you?. Check the wiring at the back of the gage and at the sender on top of the tank first. It's easy and you don't get fuel on you. Pulling the sender out is easy enough but be prepared to have a new gasket as you may destroy the old one. As pointed out above, if your float has become full of fuel or is somehow compromised the fix is a new float or sender unit. Before you remove it you might consider adding an extra ground wire, even if it is temporary it would eliminate a bad ground ( earth) at the fuel sender. Just pick a screw on the sender and run a wire to a good clean ground on the frame nearby.

 

[John Turney]

Does your heater blower motor work? If so, you are getting power to the fuel gauge. If not, you may not be getting power to the gauge. A green wire goes from the 35-amp fuse to the gauge, and from the gauge to the blower motor switch.

As mentioned by Roscoe, a bad ground at the sender is also common, especially if the fuel line from the tank to the fuel pump has been modified - run a ground wire as suggested.

 

[DarvinR]

The mgaguru.com website has quite a bit of technical info. Here's a article on troubleshooting the fuel gauge/sending unit.

Alright, I will pass this to my friend. He's looking to get this BT7 project with the fuel gauge issue. The owner wasn't sure what his eldest son did to fix it as it is still not working. We'll take a closer look soon after we finished installing the brake kit and nitto tires on the pick-up truck this weekend.

 

[LAW75]

They all look something like this

And very easy to replace. There is one YouTube out there that illustrates install. Search “fuel sender replacement on Austin Healey”. Also…very important to install a simple extra ground wire from one of the 6 screws on the fuel sender. I ran mine to the screw on the spare tire fastener. If I can fix this, anyone can

 

[bob hughes]

There was a separate earth wire on mine when I bought it so I kept it there when I rewired the car, it can not hurt to have it.



Bob