Which fuse serves the heater control valve?

[bourkeco]

New controller received, installed, problem solved. Thanks Jim & Mat!

Controller? do you mean the pannel?

[ltbrett]

HVAC controller, control panel, IHKA control module--I think on this car they are all one and the same. I am referring to the panel where the driver controls the hvac system. There are several variations on this panel, so if you are looking to replace it, be sure to match part numbers.

Brett

[bourkeco]

HVAC controller, control panel, IHKA control module--I think on this car they are all one and the same. I am referring to the panel where the driver controls the hvac system. There are several variations on this panel, so if you are looking to replace it, be sure to match part numbers.

Brett

Dam i hope mine is not bad again... where did you purchase your new panel?

[ltbrett]

I got a used panel off eBay for $70. But there are a bunch of tests to do before you determine your new panel is bad. What are your symptoms?

[bourkeco]

Some vents blow hot some cold ... I think we have narrowed it down to a bad valve...

[Marineberger1]

I have a 2003 525 with no voltage to the heater control valve. Which fuse and what other components are in this circuit? Thanks.

Brett

If your 525 is anything like the 97 528 then there is a fuse (mine was 50a) behind the glove box. Not in the glove box with the other fuses. I have also seen others with fuses in the (looks like the fresh air vent box) on the passenger side in the engine bay.

[OnTheFence]

Bumping this.
I get hot air from my upper and lower vents with the A/C on.
Heater Control Valve stuck open?
Having trouble finding videos on diagnosing and/or replacing this unit
Help?

[JimLev]

If you switch the air to the floor vents is it cold?
The heater control valves are normally open with no power applied to them.
The HVAC panel controls them with a PWM signal, on/off 12 volts.
If you pinch off the hose bringing the hot coolant to the valve does the air coming out of the vents cool down?

[OnTheFence]

I replaced the heater valve.


Since it's not mission critical and easy to replace, I got an aftermarket part for $35 (instead of $90 for Febi at FCP)


I warmed the car up and turned on the A/C
No incorrect hot air coming from the upper and lower vents anymore.
So, the new heater valve fixed the problem.


Here is the weird thing.
I opened the old heater valve to inspect how it failed.
I was expecting a failed seal or a failed solenoid plunger.
The seal looked perfectly fine, and when I applied 12V to the heater valve, it activated the cone stopper solenoid.
So, the old heater valve looks like it works. Weird.

[cnn]

Yeah,

BMW engineers are something else...

I used to have a 2007 Honda Odyssey, the dial (hot/cold) is simply a knob on the dash, which connects to
a simple valve at the engine firewall. Basically a simple mechanical device controlled by a simple knob.
Virtually bullet-proof. The only con is you have to adjust it manually.
The environment in the car is so dynamic (hot/cold, weather keeps changing, winter coats, some people are
hot and some are cold, slow vs highway speed) so I prefer the old-schooled way of adjusting it yourself.

The BMW HVAC panel is very sophisticated, set a temp and the system does everything for you.
Not sure this is the best bc the cabin environment is changing constantly...