I've been having this strange issue since I've had my 88 325iC. Basically, with everything how it sits normally, the blower only works when the key is on, engine not running (KOEOff). So here's a diagram with what I know to be good, and what not.
Now, I've found Battery voltage at connector 204 with the engine off, but key in run. EDIT: I've also found 0 volts when running at the same location. As soon as the car's started, it does not work. Initially, I blamed the ignition, wiggled the key around a bit, but nothing. So I started checking fuses and relays. Fuse 20 is fine, has never blown, so I'm pretty sure I have no shorts to ground anywhere before the motor.
Now here's the tricky part. When I swap relays for known good ones, nothing changes. Still works with the engine off, doesn't when engine is running. But if I remove Relay K5, for some reason the blower works (perfectly I might add) both when in the run position and when running. I believed before that K7 ran the blower, but that's all out the window now.
So my question is, does the blower NORMALLY work Key on engine off? or should it only work when running? And second, how would replacing (plugging in) or jumping a relay, allow something to NOT work like intended, yet when unplugged, works as intended?
Maybe there's something simple in there that one of you have experienced, so lend me your vast knowledge!
Thanks
Now, I've found Battery voltage at connector 204 with the engine off, but key in run. EDIT: I've also found 0 volts when running at the same location. As soon as the car's started, it does not work. Initially, I blamed the ignition, wiggled the key around a bit, but nothing. So I started checking fuses and relays. Fuse 20 is fine, has never blown, so I'm pretty sure I have no shorts to ground anywhere before the motor.
Now here's the tricky part. When I swap relays for known good ones, nothing changes. Still works with the engine off, doesn't when engine is running. But if I remove Relay K5, for some reason the blower works (perfectly I might add) both when in the run position and when running. I believed before that K7 ran the blower, but that's all out the window now.
So my question is, does the blower NORMALLY work Key on engine off? or should it only work when running? And second, how would replacing (plugging in) or jumping a relay, allow something to NOT work like intended, yet when unplugged, works as intended?
Maybe there's something simple in there that one of you have experienced, so lend me your vast knowledge!
Thanks
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