I'm having problems with my battery not being charged by the alternator and need some help.
New battery. Alternator bench tested all ok.
Engine running, alternator all connected, voltmeter over the battery shows approx 13 volts, however you can watch this decay continuously. Battery will run flat in 1-2 days.
Disconnecting the multi-pin plug on the top of the alternator, engine running, battery is getting a steady 13.8V charge.
Multi-pin plug only has one wire, which is blue.
What is this wire for? Can I leave the plug disconnected?
Does anyone have a charging circuit / alternator wiring diagram in pdf format?