Fixing a BMW Climate Control Unit myself (Savings $400)

Jmiller · August 29th, 2006, 06:54 PM

Alright, so I havve a friend who is the owner of an e36 bmw, which have an inherent flaw in their climate control unit. There's a bad capacitor that needs replacing, and upon figuring out what to do, my friend and I made a radioshack run.

$22.60 bought us a soldering iron, solder, a desoldering vac, and a 47 uF electrolytic capacitor. Now came the fun part.

First, we removed the BMW Onboard Computer, as it was the only way to get access to the climate control unit which sat on top of it. This proved to be a little more tricky than we intially hoped for, but once we got the right technique (press upwards hard to release the unit) it slid right out. The nice thing about this is that you can leave it connected. The climate control unit sits on top of it, and I got that to slide out fairly easily. There's two cables connected to the back of it, which unhooked with a little bit of tugging.

The removed Climate Control Unit:

http://www.retrosix.net/public/bmw/controlunit.jpg

After we got that out, it was time to open it up. Four screws held the plate together, which came out with a small flathead screwdriver. We also had to remove the fan from the unit also. It serves to draw air in to test the internal temperature of the car. That came off pretty easily. The circuit board however was a little more challenging. We both used tiny screwdrivers to force it out. Not idea, but it got the job done.

On that board, there's a big blue connector, and right in front of it, a blue capacitor. Next, we flipped the board over and desoldered the capacitor. There's a small resistor you have to make sure you don't ruin with the soldering iron. This was a little tricky, as I have zero soldering experience. Once we got that out, we cleaned the holes so the new capacitor would slide in easily. We put the new one in, paying attention to the polarity. The positive and was on the right. After a Soldering 101 lesson from the internet, we managed to solder in the new capacitor correctly without ruining any of the surrounding electrical components.

The new capacitor soldered onto the circuit board:

http://www.retrosix.net/public/bmw/solder.jpg

Now it was down to reassembly. Essentially just working in reverse, I put the unit back together while my friend was off taking a phone call. It was much easier to slide the unit back into the car than it was to remove it. We reconnected the two wires to the control unit and slid it back in. Then we also had to put the onboard computer back in. Again, very easy. We turned on the car, and luckily everything worked.

Success! -- Working Climate Control Unit!

http://www.retrosix.net/public/bmw/finished.jpg

Not bad for $22 and a couple of burned fingers.

If anyone wants to do this to there BMW the site is
http://www.macadamizer.com/bmwfix.html

sandor_ · August 29th, 2006, 10:38 PM

awesome. what was the symptoms that lead you to replacing the capacitor?

i've got a '97 328i, so i might be in the market for this fix in the future.

C53A_4G63T · August 30th, 2006, 12:59 AM

Entensity.

Jmiller · August 30th, 2006, 04:10 AM

Quote:

Originally Posted by sandor_

awesome. what was the symptoms that lead you to replacing the capacitor?

i've got a '97 328i, so i might be in the market for this fix in the future.

Its not my car but I believe the symptoms were the all of the climate controlls worked only once and a while probably about 15% of the time. They worked on there own for only a few seconds each time. From my understanding this is a very common problem on the e36 bmw's

sandor_ · August 30th, 2006, 01:38 PM

Quote:

Originally Posted by Jmiller

Quote:

Originally Posted by sandor_

awesome. what was the symptoms that lead you to replacing the capacitor?

i've got a '97 328i, so i might be in the market for this fix in the future.

Its not my car but I believe the symptoms were the all of the climate controlls worked only once and a while probably about 15% of the time. They worked on there own for only a few seconds each time. From my understanding this is a very common problem on the e36 bmw's

interesting. i dont have that problem yet (107,xxx miles) but i did have the ignition switch lock up (order new one from germany, drill out the old...) and the back light on the radio went (replaced with an after-market with CD and aux input) and the clock's backlight just went.

i'll keep this info bookmarked, because it is probably only a matter of time.

thanks again! images/smilies/cheers.gif

bone · August 30th, 2006, 03:30 PM

makes you wonder how much money you can make by scaveging containers for broken electronics, if you see how easy it is to repair this

that site you got the info from is funny though, a complete site about a trip he made in europe, and then, as last sentences

Quote:

Looking for Something Completely Different?
If you are looking for info on how to fix your Climate Control Computer on your BMW, click here.

ArosaMike · August 31st, 2006, 12:58 AM

Ha. We had an e36 BMW pool car when I did my Gap Year and that had exactly that problem....only the buttons worked 0% of the time images/smilies/tongue.gif

LOL Was a pain cause it used to heat the car in the summer sometimes! Ouch!

August 29th, 2006, 06:54 PM	#1
Jmiller Joined: Mar 26th, 2005 Last Online: January 5th, 2009 Location: Midwest USA Posts: 295 Car: 2001 Oldsmobile Aurora 3.5 Rep Power: 18	Fixing a BMW Climate Control Unit myself (Savings $400) Alright, so I havve a friend who is the owner of an e36 bmw, which have an inherent flaw in their climate control unit. There's a bad capacitor that needs replacing, and upon figuring out what to do, my friend and I made a radioshack run. $22.60 bought us a soldering iron, solder, a desoldering vac, and a 47 uF electrolytic capacitor. Now came the fun part. First, we removed the BMW Onboard Computer, as it was the only way to get access to the climate control unit which sat on top of it. This proved to be a little more tricky than we intially hoped for, but once we got the right technique (press upwards hard to release the unit) it slid right out. The nice thing about this is that you can leave it connected. The climate control unit sits on top of it, and I got that to slide out fairly easily. There's two cables connected to the back of it, which unhooked with a little bit of tugging. The removed Climate Control Unit: After we got that out, it was time to open it up. Four screws held the plate together, which came out with a small flathead screwdriver. We also had to remove the fan from the unit also. It serves to draw air in to test the internal temperature of the car. That came off pretty easily. The circuit board however was a little more challenging. We both used tiny screwdrivers to force it out. Not idea, but it got the job done. On that board, there's a big blue connector, and right in front of it, a blue capacitor. Next, we flipped the board over and desoldered the capacitor. There's a small resistor you have to make sure you don't ruin with the soldering iron. This was a little tricky, as I have zero soldering experience. Once we got that out, we cleaned the holes so the new capacitor would slide in easily. We put the new one in, paying attention to the polarity. The positive and was on the right. After a Soldering 101 lesson from the internet, we managed to solder in the new capacitor correctly without ruining any of the surrounding electrical components. The new capacitor soldered onto the circuit board: Now it was down to reassembly. Essentially just working in reverse, I put the unit back together while my friend was off taking a phone call. It was much easier to slide the unit back into the car than it was to remove it. We reconnected the two wires to the control unit and slid it back in. Then we also had to put the onboard computer back in. Again, very easy. We turned on the car, and luckily everything worked. Success! -- Working Climate Control Unit! Not bad for $22 and a couple of burned fingers. If anyone wants to do this to there BMW the site is http://www.macadamizer.com/bmwfix.html __________________ My Animated Christmas Lights (Full Videos)

August 30th, 2006, 12:59 AM	#3
C53A_4G63T Joined: Jun 30th, 2005 Last Online: 05:36 AM Location: Farmington, Connecticut Age: 22 Posts: 544 Car: 99' Infiniti Q45t, 89 Mitsubishi Mirage Turbo Rep Power: 17	Entensity. __________________ 1989 Mitsu Mirage Turbo Hatch, 4G63T swap and more goodies to make it a low 12 sec car. Better to own a Volvo, than be owned by one. I work for Buick....... and it's not nearly as fun as it sounds.

August 31st, 2006, 12:58 AM	#7
ArosaMike Resident Kart Racer Joined: Apr 30th, 2005 Last Online: December 28th, 2008 Location: Birmingham, UK Posts: 839 Car: SEAT Arosa Sport LFS Status: Rep Power: 15	Ha. We had an e36 BMW pool car when I did my Gap Year and that had exactly that problem....only the buttons worked 0% of the time LOL Was a pain cause it used to heat the car in the summer sometimes! Ouch! __________________ It's Pain Time...Wooooh

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August 29th, 2006, 10:38 PM	#2
sandor_ Joined: Mar 16th, 2005 Last Online: December 28th, 2007 Location: Philadelphia, USA Age: 28 Posts: 1,043 Car: 911, 328i, Golf, '71 Vespa Sprint Rep Power: 0	awesome. what was the symptoms that lead you to replacing the capacitor? i've got a '97 328i, so i might be in the market for this fix in the future.

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