QuestionHoward
First, thanks again for the help on the MGB starter. You were spot on.So now, I seem to another issue with the Alternator.
When I connect the battery, the altenator starts smoking from the back cover (smells of burning). Until now I have not had the altenator connected due to this issue. On trouble shooting I have found a few things:
a)when I try to re-start the car, the starter wont turn over again, but will once the altenator is disconnected.
b) If I disconnect the altenator and put a continuity tester on the altenator, the pins which would connect to the brown wires, have a completed circuit to ground.
c) when reconnected, the red altenator light is on always, except when I turn the ignition on, then it goes off.
Any ideas?
Andy
AnswerHi Andy,
IF YOU HAVE YOUR BATTERY CONNECTED UP CORRECTLY (Neg ground) You must not have any connection to ground with the Brown wires. A simple test is to disconnect the brown wires and connect a 12v test light between the brown wires and the Alternator terminals and the light must not light. If it does the alternator is bad. (diode pack most likely) No further alt test necessary.
Depending on what year model, if you have the three wire system (a large brown and a small brown and an idiot light wire) The two brown wires are (+) all the time and the idiot light wire is only hot with the key on and the method to test the charge light (idiot light) is to first check it with a volt meter and it should be dead. Then turn the key to ignition only and it should show 12v when disconnected from the Alt. Then with that wire disconnected from the alt watch the idiot light and ground the end of the wire and the light should light up. End of test of the wiring system.
With a new or rebuilt alt installed you should not see any spark at all when connecting either of the brown wires. The charge light (idiot light) should be out (key off). Then with a volt meter connected to the battery (12.5+v) start the engine and set the idle at fast idle (1500 RPM) and read the volt meter. (13.8 to 14.5v not over nor under) End of test.
Howard
