We are repairing a Porche 924 nonturbo. We have changed the alternator and battery, but the alternator is not holding charge. We need a diagram to see where the problem lies. Thanks
You need electricity 101. Alternators do not "hold" a charge and I suspect a diagram would be of little use to you. A diagram will not magically put you on the problem but some basic trouble shooting techniques will isolate it in short order. First step is to identify the problem and I guarantee it is not "alternator is not holding charge". Alternators charge the battery among other things. what is the voltage reading at the battery with the engine running at 2k rpm? at idle? Is the alternator charging? Does the battery pass a load test? I don't care if it's new, does it pass? Is there any indication of a parasitic load? If yes to what fuse did you isolate it to? You do have a VOM right? You have done these tests right? if no then perform the above. A diagram will be of no use to you at this point.
the alternator doesn't hold a charge, it gives a charge. if it's not putting out then you will need to check to see if the field wire is energized. that will be the small wires on the alternator.
you may well not need a wiring diagram as the charging systems are quite straightforward ,usually it is a regulator problem 2 types. 1 screwed on at the rear of the alternator half the size of a match box 2 metal box usually in the engine bay { bridge the 2 lower terminal,s to by pass the reg} best bet though is to remove the alternator for a bench test at the local auto electricians, and double check the battery if you are still having problem,s you need to look for any voltage drop on thick cable,s in the engine bay 1 red 2 brown