This is for an XK150 over here in England which has been rebuilt by somone I know through the MGCC (he also has an MGA twin cam)
Barry is handier with the spanners than a multimeter or computer and asked me for help on his fuel gauge. The low level light was OK but the contents always showed zero. We have made some progress and the sender is fine, the wire to the potentiometer buzzes out OK and when you remove the gauge and put it across a 12v battery it doesnt register with either polarity applied. You can get the needle to move by adjusting 2 screws on the back though.
Seems clear cut, get a rebuilt gauge, whats bugging him is that he changed to -ve earth and alternator and wonders if that caused rhe problem. These are usually bi-metallic to give an averaged reading and not polarity fussy but I wondered if anyone here kmows for sure, or any other checks you can do. Also, he has jusr spent £150 on a rebuilt ammeter after the existing one burnt out. (so is a bit gun shy over another £100 for a fuel gauge, I can see that)when he converted he swapped the ammeter connections over and it worked fine, however he has been told that the alternator conversion is known to burn out ammeters. It reads fine, exactly how I remember mine in a 1965 Spitfire I owned in err 1965 :-). Shows a few amps charging current for 2 or 3 miles after a cold start then sits pretty much on 0. Has anyone here experienced ammeter problems with an alternator conversion?
Thanks a lot for any help in advance.
ps , Its a really nice car. I will get some pics next time I'm there.