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Just ran into this problem today on my '01 X5 3.0i 5spd.

The ac control was acting strange on first morning 20 minute drive . . . slow to respond and lacked full control of speeds, temps, vents, etc. When I shut off the car, everything went off.

Upon return two hours later, opened the door to the ac fan running on high WITHOUT THE KEY IN THE IGNITION.

When I started the car, the ac control panel was completely black, and not surprisingly, all buttons had no effect. During the drive home the unit only blew hot air.

The blower continued to blow after car was turned off, key removed, and car locked.

I removed the ac control panel from the dash and disconnected the light blue canon-plug . . . this stopped the blower.

I have read through many of the posts here regarding ac control problems and the problematic FSRs. I pulled mine out and it looks like the replacement FSR shown in the Final Stage Resistor Replacement DIY on this site (pic attached).

Any experienced ideas, bad FSR, control unit, or something else?

Thanks - Darrell

DS. I think just based on your irratic fan operation, your FSR needs to be fixed or replaced. There is actually a DIY for fixing it on here. Just search for that. Or buy a new one from dealer. I prefer getting in touch with Craig at Bloomfield BMW. No one comes near his pricing.

Fixing the FSR requires some soldering skills.

HVAC Control Inop - Fan Hot Powered!

Thanks for the reply SlickGT1.

I'm not against going after a bad fan, but only for just cause.

Do you have experiential reason to believe that my fan could be bad if:

1. It is continuously blowing at a high speed?
2. The AC control panel was intermittent for 20 minutes before going dead?
3. During that time the vent valves and temperature controls were ineffective?
4. The fan stays on and maintains its speed even after the key is removed from the ignition and car locked?

If you do, I'll start suspecting the fan. - DS

Shit stupid auto correct. Sorry. FSR. Not fan. Replies the FSR. Going to edit that post. Sorry, iPhone ownage.

HVAC Control Inop - Fan Hot Powered!

Just received my Meyle (Germany . . . part made in PRC!) replacement FSR from Bav Auto.

I had not run the truck for 3 days. Put in the new FSR, reattached the blue harness to the back of the IHKA and NO HOT POWER to the blower. So far so good.

Started the truck and everything began to work fine. The IHKA was all lit up and controlled the blower, vents, and with the temp set to 60, cold air was blowing out of the vents front and back. The engine was still cool so I checked to see that the aux fan was running and it was. I wanted to ensure that the a/c was turning it on and not a water temp switch.

THEN . . . within 10 minutes, the IHKA began to flicker slightly and eventually die again. I turned the vehicle off and removed the key. All was quiet and then I heard the blower begin to spin and slowly spool up to full speed. Same deal all over again. I disconnected the blue IHKA harness to stop the blower once again.

Disconnecting the black harness will also stop the blower. Whenever I reconnect the harnesses, the blower begins to spool up to full speed again with or without the key in the ignition.

Ideas?

Ok now that is some strange shit. What would cause the blower to go full blast with a good FSR? I have to think.

HVAC Control Inop - Fan Hot Powered!

Took her in yesterday for dealer diagnosis. Bad controller.

Paid $520.30 for a new controller and so far (~ 3 hours of use) so good.

The original FSR that I replaced is probably still good. Will keep that in the SAV as a spare if my replacement FSR craps out.

Anyone need a replacement front panel for their IHKA controller?

Damn, well now we know this can do it too.

After much delay, the hvac control is repaired. To make a long story short, the control head needed to be replaced. Found Hi-Tech Electronic Services in CA (800)580-3376 who initially thought they could repair my existing unit. However circuit board was on backorder and after several weeks found he could order an exchange for couple hundred dollars which we did. Dealer wanted $500 + for new one. One word of caution that most may know, there are at least two different heads for this and similar year models. The difference is the number of pins in the black connector. Be sure you count them and let Hi-Tech know which you need. That would have saved me a couple of weeks back and forth. Thanks to all who contributed.