QuestionMy car is a 1971 MG Midget 1275 registered in England although now residing in Southern Ireland.I parked the car up with no problems [or so I thought] a couple of days later I went to start it to find the battery flat,not thinking to much about it I took the battery off and charged it.After refitting the battery I confidently went to start it,but to my despair it wouldn't the starter never turned although the fuel pump clicked I then noticed the ignition light was on when the key was turned off on off when the key was on.I would be grateful if someone can shed a little light on this problem .
AnswerHi There, Mendit. The ignition light is typical of a sticking cut-out inside the voltage regulator box, but I am concerned that the starter no longer operates. It is unusual to have two problems, but I think you have (1) a faulty starter solenoid and (2) a faulty voltage regulator.
1) With the engine switched off, run a wire directly from the battery and touch the SMALL terminal on the solenoid. It should operate the solenoid and cause the engine to turn over. If it doesn’t, then the solenoid is faulty. If it DOES operate the starter, but you cannot turn the engine over with the key, then get back to me because you have a different problem
2) The cut-out is a mechanical relay that disconnects the dynamo from the battery until it is producing enough voltage to charge the battery. If it stays connected when you switch the engine off, then the battery will discharge through the electrical windings of the dynamo and this would cause a flat battery and a hot dynamo.
Look for a big black box with several wires connected to it. It will be labelled LUCAS RB340, and it should be just above the fuse box. Take the lid off, and inside you will see three large relays with adjuster cams on top and points underneath. The cut-out is the one on the right. With the engine switched off, the points should be open. My guess is they are shut.
You should be able to rock the relay, pulling the points open. Try cleaning between them with a small piece of cardboard. Do not use sandpaper or emery cloth, they are too harsh.
If the points still won't stay open, try turning the adjuster until the points just open, then start the engine and adjust the tickover to 1,200 rpm. Turn the adjuster until the points just close. Switch off the engine, and the points should now be open. If this doesn't work, you need to replace the entire voltage regulator unit.
Finally, remember to lower the tickover setting when you have finished.
