No, I am not doubting their capabilities, but it happens only after running the engine for a period of time before the alternator starts to provide insufficient charge.
Sometimes when contacts are bad, it shows a good reading during testing and initial running. When the circuit heats up, resistance increases and it is unable to provide the proper connection and that is when it starts to give problem.
I would suggest stripping the alternator to check for bad internal connections.
Normal ECU output voltage is 4.5 to 5 v, so it should be around that.
There are ways to test but you need to remove the ECM socket for this circuit at the same time leaving the engine wires to ECM connected. I am not sure of the wiring circuits for your car so I do not know which socket to disconnect.
You can test it by checking the voltage
Tuesday, July 8th, 2008 AT 6:40 AM