QuestionThe fuel (petrol) gauge on my 1980 MGB failed yesterday. I had the contacts for the fuel tank connections tested as well as the wires connecting the "gauge" by a mechanic and it seems to me that the "gauge' is bad. Someone told me that the gauge can be rebuilt but at a high price. What is your take on my conclusion that the gauge is bad? Do they still make gauges for the 1980 MGB?
Thanks
AnswerHi John. I cannot remember ever having a bad fuel gauge. They are virtually bullet-proof. Normally, a problem with the gauge is either
a) A faulty sender unit inside the tank
b) A bad earth (ground) which should be attached to the sender unit.
c) A faulty voltage stabilizer unit (which supplies 10 volts to the gauge.
I would start by disconnecting the wire to the sender unit at the tank and touching it to earth. With the ignition turned on, if the needle of the gauge immediately starts to rise, there is nothing wrong with the gauge or the voltage stabilizer.
To answer your question, gauges are no longer available from Moss Motors (USA) but they are still available from Europa Spares for about $100 (US dollars). Alternatively, buy a good used gauge from a specialist sports car breaker such as Andy Jennings. He will sell you one for less than $20 plus airmail postage.
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If the above test fails, do not give up. It could be the voltage stabilizer. Disconnect both wires from the back of the gauge. Connect one terminal directly to the purple side of the fusebox and momentarily connect the other terminal to earth. If the gauge immediately starts to rise there is nothing wrong with the gauge and the fault lies elsewhere. Do not leave it connected or you will overheat the gauge.
