No heater blower, fuse 20 keeps blowing.

[MaxBell]

My car is a 1986 325e with an M50 swap. And NO A/C. (compressor, rad, fan, etc have all been removed)

Ok so here are my symptoms:

1. The blower will not turn on.
I'm trying to remember, but I'm pretty sure it turned on before my engine swap. I only had the car for a couple hours before it went under the knife.

2. Fuse 20 will blow if I turn on the fan.
Doesn't matter if the temp control is at A/C or heat. It will blow after 30 seconds on Fan 1. If I put it to Fan 4, it blows instantly.

3. The snow flake and recirculate buttons stay lit, but go out when i turn the fan to 1, 2, 3, or 4. (they are on when it is at 0)

So far, I have taken the console apart, no shorts. The heater core valve was replaced recently, it's all plugged in properly.

I have no A/C so I don't know what plugs are hanging out in the car, possibly causing problems.

The M50 makes it hard to get at the blower, should I be testing that somehow?

[jlevie]

The first check would be to disconnect the blower and see if the fuse still blows. If it does there is a short in the wiring. If it doesn't, the blower is shorted.

[5Toes]

This is funny, cause I did the same thing to my car and have the same damn issues.

Check the unloader k7 relay is what I have read. If it is bad your power windows will also not work

http://bmwe30network.net/forums/read.php?3,8221,8221

Hope you figure this out. My fuse 20 doesnt look blown though

[MaxBell]

The first check would be to disconnect the blower and see if the fuse still blows. If it does there is a short in the wiring. If it doesn't, the blower is shorted.

Where do I go to disconnect the blower? The M50 blocks that little door in the engine bay rather severely. :( Is there somewhere else to disconnect it?

This is funny, cause I did the same thing to my car and have the same damn issues.

Check the unloader k7 relay is what I have read. If it is bad your power windows will also not work

http://bmwe30network.net/forums/read.php?3,8221,8221

Hope you figure this out. My fuse 20 doesnt look blown though

Well my windows all work, and all the relays have already been replaced with known good ones. I'll double check either way though.

[MaxBell]

For future Google Searchers.

The blower motor bearings were seized, which made it too difficult to turn and made the Fuse # 20 blow.

The resistor pack was also shorting out, but that wouldn't have had any affect when the fan was on setting 4. (since there's no resistor for that setting, only 1, 2 and 3.

[88e30J]

I know this is a 10yr old post but.. Thanks for the follow up. This was also my exact issue and I was dreading chasing wires all over the place trying to find a dead short. Thankfully I found this and it was also a seized squirrel cage.