Alternator Issues Again

[DougPEX5]

Originally Posted by oldskewel

4 Amps is about the right number to be flowing through the field windings (through the slip rings) at battery voltage. E.g., 12V supply, 3 Ohm field winding resistance = 4 Amps current through there if the negative side of the windings is grounded.

So that might give you a clue about where to look for the problem in case you are thinking about diagnosing or even fixing it yourself. I know it would be nice to just get a free replacement one that works, but ...

Sometimes, as I've noticed on a reman alternator purchase many years ago on a different car, something as simple as using little Phillips head screws that hold the VR in place, etc., which are too long can cause an internal short. I.e., the screw is supposed to hold the VR to something, but since the screw is too long, it goes through further and barely, intermittently, maybe after a year of vibration, touches a ground, leading to a problem like this.

Could also be a failure within the VR circuitry that holds a switch open when it should close. That would be exactly the sort of thing Chinese companies are notorious for - cutting costs on electrical circuits, since they can work perfectly for a brief period before failing once they are off the hook.

Thanks I WILL remember that. One last time with Bosch remanned. I did get what NAPA said was the last replacement in the US, so I’m taking one for the team if it’s junk. From now on new only. I have gotten really quick at changing these water cooled alternators out!


Sent from my iPhone using Tapatalk