[Clammy]

First, a little background:

My '06 330i came with plain black knobs on the radio head unit and AC/Heater Control panel. I bought a newer head unit, to address the faded LED display, and in order to be able to code for USB input, and it came with the nicer aluminum highlighted knobs. This made the plain black AC/Heater control knobs look even uglier than before, so I picked up a used later model AC/Heater control unit off Ebay, with the aluminum highlighted knobs to match. Yeah, it's a silly little thing, but it bugged me, and I got the used one off Ebay for 20 bucks delivered, so...

So, the plan was to just swap the units, but the one I got off Ebay had sticky buttons, so I decided to just transplant the face, with the nicer knobs, onto my original control unit. It went smoothly, and everything seemed to be in order, until I went for a drive today. It's winter here, and the temperature today is near freezing, so I got in the car, and hit the "AUTO" button and rolled the temp up to max heat (28C), and left for my destination. The first weird thing I noticed was that right away, the fan was blowing at almost full blast, which usually doesn't happen until the car is warmed up. So it's blowing cold air, as the engine was cold. I figured as I would be driving and the engine warmed up, so would the air... well, the engine warmed up alright. The oil temp was around 200F (I reprogrammed the instant fuel economy gauge on the tach to show oil temp, and replaced the tach face with one that has the oil temp gauge on it from a 335i), but the air was still ice cold. So, I thought I must have screwed something up, and I would figure it out when I got home. I was wracking my brain trying to figure out how just changing the faceplate would cause this weird behaviour. Then I had a thought, maybe I reversed something somehow, and the car thought I wanted air conditioning at the lowest temp (16C), so I rolled the temps (both the driver and passenger sides) down to 16C to see if anything changed... it didn't. She was still blowing ice cold air. In frustration, I rolled the temp (both sides) back up to full heat (28C), and BAM, it started blowing hot air!!

So, I think what it was is that I needed to reset the range, by rolling the dials all the way down, and all the way up. There are 2 potenitometers, or rheostats, mounted on the circuit board, that each have a gear on them, that fits into the gear on the temp dials. I guess taking it apart, screwed up the range, and it just needed to be reset.

So, if you ever have this issue, try doing a full sweep back and forth with both dials, and see if that fixes it.

Cheers!

[200,000 club]

You should read the bently manual on the 3 series, it explains how the entire IHKA heat/ac system works

[colorado.e9x]

This thread is nearly a year old lol

[200,000 club]

Originally Posted by colorado.e9x

This thread is nearly a year old lol

Yea I realized, better late than never lol