Heater not blowing air

[Kheadley]

It's cold as hell here and my heater isn't blowing any air at all, thank goodness my windshield heater still works. Is the cause likely the blower motor or some electronic? Its confusing me because the front windshield heater still works but all the front vents don't blow.

[Lester]

Are you sure the vents are open? They are open/closed using the knurled knob beside each vent. If the blower is working on defrost (front window), then there is no obvious reason the air vents won't work.

[Tommm]

If you had a fourth generation F body I would tell you that a vacuum line goes under the battery. The acid leaks and puts a hole in the line so the HVAC defaults to safety mode and only goes up the defroster vents.

Does BMW default to defroster vents only if something goes wrong in the system?

[Kheadley]

e82
I think it's a battery thing because it's been so cold (Alberta -30c average this week), after going for a long drive it kicks back in mostly.

[Edrift]

When this happened to me my water pump died and the engine overheated.

[Lester]

When my water pump died, the radiator fan kicked in. I could hear it, that is what clued me to the problem. But that is under the hood, and shouldn't have anything to do with the interior blower vents.

[Kheadley]

I went for a long drive and it fixed itself, cause was probably me doing short drives lately.

[lab_rat]

Originally Posted by Kheadley

I went for a long drive and it fixed itself, cause was probably me doing short drives lately.

My experience:

Short drives are often the most severe on cars, and it seems like BMWs like to 'stretch their legs' fairly regularly or they tend to find their way into a cantankerous mood.

[mr.fabulous]

Have you had the blower motor wiring recall? Does it not run for a bit when you first start the car but eventually kick in? That was my experience and so I bought a replacement blower (just in case) and ultimately replaced the thing when it finally died altogether.

[Kheadley]

It was just a low battery