battery drain from Heater/AC circuit
95 BMW 528I Series 5
My wife said the heater would sometimes go off by itself then come back on. Until yesterday it did not affect the battery voltage.
Now a faint buzzing sound behind radio with key off drains battery down to 7 volts. Recharge to 12.5 volts and in 10 minutes back to 7 volts Battery is only 3 months old,
Taking out #9 fuse in the glove box stops the buzzing. I see #9 supplies the Heat/AC control Module circuit. Before I do any further dismantling I thought I would ask is there a specific motor or other electrical device more prone to failure.
Any ideas are appreciated.