QuestionQUESTION: Got in my 52MGTD and drove 2 blocks and the car just quit. All electrical seems to be working. Engine turns over although I do not see any spark when taking plug out and turning engine over ??
After reading other posts I did leave ignition on and pried points apart and I did not see any spark there, should I have ??
Are there certain places I can take ohm meter and test for voltage etc ??
ANSWER: Hi John. A sudden engine failure is usually electrical, and your lack of spark confirms this. With the ignition on, you should see a small blue spark when you pry the points open with your fingernail.
Just to be sure, before you start tracing an electrical fault, I would take the lid off one of the carburetters and check that you have fuel in the float chamber.
At the side of the distributor there is a small electrical terminal with a 2BA nut on it. Put your ohm-meter on the VOLTS setting, attach one volt-meter wire to the nut, and attach the other voltmeter wire to earth. With the points shut, the meter should read zero, and with the points pried open it should read about 12 volts. Also, the SW terminal of the coil should read 12 volts, and the resistance between the CB terminal of the coil and that nut on the distributor should be less than 2 ohms.
I have seen quite a few TDs where the reduction gearbox on the back of the dynamo has flopped down and touched that nut. It earths the distributor points and kills the engine.
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QUESTION: There is no 12 volt reading on terminal with points open. I disconnected this wire from the coil to distributor and checked both posts on the distributor and now power on either side ??
AnswerHi John. If I understand you correctly, there is no 12 volt reading at the side contact of the distributor with the points open, and there is no voltage at either post on the coil?
If there is no voltage at the coil, then you have a total failure of the ignition circuit.
1) Check that terminal A3 on the fusebox has 12 volts with the ignition switched on.
2) Is power reaching the fuel pump? It shares the same wire.
3) Has the ignition switch failed? Maybe a wire has dropped off the back of the switch.
One last thought. The car was originally wired positive ground, so if you are using an analogue volt meter, perhaps the wires need to be reversed to get a reading on the meter.
