QuestionQUESTION: I have a 1980 MGB. When the key is in the running position and the car is not started, there's a nasty buzz from the battery. What's up with that? How should I go about diagnosing it?
Not sure if it's related, but at this time and any time the car is running, the HAZARD warning light is on. Not sure if that's related, but there's no working hazard light switch.
ANSWER: Hi Billy,
Fix one thing at a time and they may or may not be related. First there MUST not be any noise coming from any battery. First put the car in the position that it makes the noise and be sure it is the battery and not something near the battery. Lightly touch the battery posts to see if either is getting warm. If so, you need to turn everything off and remove and clean the cables and the posts and reinstall to see if the noise stops. If the noise is truly inside the battery you need to replace the battery immediately. No battery should make any noise. If it is truly making a noise it can possibly explode.
When a battery is charged it is causing electrolyses of water which separates the hydrogen and Oxygen that makes water. If the buzzing noise is a spark arching, that equals an explosion.
When that is corrected then proceed to the hazard light problem if it is still a problem. Let me know the results.
Howard
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QUESTION: I had the battery fully tested and cleaned all the contacts. The noise is still there. To clarify, it's a rapid clicking. Pretty sure it's coming from somewhere around the negative post or the cable grounding it.
It occurs when I jump the ignition coil to the fuse or when the key is in position 2 and the car isn't running. Doesn't happen when the car is starting or running.
Should having the key in position 2 put the same load on the battery as jumping the ignition coil?
ANSWER: Put your hand on the starter solenoid when you hear the clicking to see if that is what is clicking. If it is, you can feel it. If that is not it put your hand on all of the relays you can find to see if they are clicking. A BATTERY CAN'T CLICK!!!
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QUESTION: Once I removed the carburetor, the answer became obvious. Putting the key in the On position resulted not only in the clicking, but in gasoline spewing all over. The noise is the fuel pump, which is inches from the battery's negative terminal. So... why is the fuel pump going full blast when the engine isn't running? I pulled the inertia switch plunger so I can continue my electric work, but I'm clearly lacking understanding of this matter.
Thanks for your patience!
AnswerIf your car still has the original SU fuel pump it should click not buzz. Electric pumps on just about all cars run all the time that the ignition is on. The SU pump would slow it's rate of click when the float chamber/s were full and it would finally quit clicking completely except for an occasional click. If your pump buzzes, then it is an aftermarket replacement pump of some kind. It would be wise to check the fuel pressure as some aftermarket pumps are too high in fuel pressure. You don't want over 3 PSI at the carb.
Howard
