Austin Maxi fuel gauge not working

[hernerover]

A couple of months ago the fuel gauge on my Austin Maxi stopped working. I quickly identified that the fuel tank sender had died of old age. I purchased a new old stock item on Ebay. When I installed it, it worked fine. Over the next couple of weeks I concentrated on fixing electrical faults with the sidelights and hazard lights. Then, I decided it was time to run the engine and charge the battery at which time I noticed that the fuel gauge had stopped working. Oh bu**er i thought. I removed the sender from the tank and checked for operation by connecting the power lead back up and earthing the sender to the boot floor and moving the swingarm manually and it worked fine. The problem I have is that when I put it back into the tank, I get no reading on the guage. 

I have absolutely no clue what the fault is and have even replaced the voltage stabiliser unit to no effect.

Can anybody on here give me any advice???

[truckdoctor]

Any fuel in the tank?

[Rich]

Jul 9, 2020 14:29:55 GMT hernerover said:

A couple of months ago the fuel gauge on my Austin Maxi stopped working. I quickly identified that the fuel tank sender had died of old age. I purchased a new old stock item on Ebay. When I installed it, it worked fine. Over the next couple of weeks I concentrated on fixing electrical faults with the sidelights and hazard lights. Then, I decided it was time to run the engine and charge the battery at which time I noticed that the fuel gauge had stopped working. Oh bu**er i thought. I removed the sender from the tank and checked for operation by connecting the power lead back up and earthing the sender to the boot floor and moving the swingarm manually and it worked fine. The problem I have is that when I put it back into the tank, I get no reading on the guage. 

I have absolutely no clue what the fault is and have even replaced the voltage stabiliser unit to no effect.

Can anybody on here give me any advice???

Sounds like you have no earth to the fuel tank..

[hernerover]

Firstly, there is about half a tankful of Sainsburys finest in the tank,
Secondly, I have checked for continuity between the body of the sender unit and the neck of tank where the locking ring goes and get full scale deflection. Tank itself bolts directly into the bodyshell.

[Rich]

Jul 9, 2020 19:03:28 GMT hernerover said:

Firstly, there is about half a tankful of Sainsburys finest in the tank,
Secondly, I have checked for continuity between the body of the sender unit and the neck of tank where the locking ring goes and get full scale deflection. Tank itself bolts directly into the bodyshell.

Worth just checking by earthing the tank sender direct to the body, just to be sure.

[hernerover]

I have just tried that, and still nothing. In the morning I'll remove the sender and test it again......

[Phil H]

Continuity with a multimeter, or confirmed by a good old test lamp? Could just be a high (in relation to the sender reading) resistance connection. Two painted (or one painted and one rusty) surfaces do not make a good connection. A damp one, however, can as it makes the same connection that makes a battery work.

[hernerover]

I used a test lamp and cleaned the mating surfaces. After further testing i think my new old stock sender is defective, it works fine at full deflection, but not at all below between 1/2 and 2/3rds full !