My alternator has been draining my battery in my Datsun 240z since I swapped the engine (VQ35). It takes around 4 days to drain the battery to the point I can't start it. It charges it fine when the engine is running.
The symptoms are after driving the car letting all the electronics chill out for a minute the battery will drain 0.17A. If I then disconnect the alternator B+ wire it'll drop to about 0.02A at which point I can reconnect it and still only get 0.02A.
I've tried disconnecting all sorts of things but the only thing that helped was the alternator. This is my third alternator since the swap and they're pretty expensive. The first two I swapped because I was pretty sure they had bad diodes - the place I've mounted the alternator gets pretty hot & I've since built a shroud for it - they had slightly different symptoms thou, after reconnecting they'd still drain hard out.
The one I have now has professionally rebuilt and tested and has done this since I put it in.
So have I done something wrong with my wiring? The obvious answer is I have a bad diode, but it seems odd that disconnecting and reconnecting the B+ fixes it.
How can I work around it? I'm almost considering having a switch on my B+ terminal to isolate it. I potentially could have a relay on it so it switches on/off when I start the car. My concern is the amount of amps it'd have to deal with?