BMW 740i E38 Climate Control Unit
 

Hello guys,
Could someone kindly help me with this:
My climate control unit will work intermittently... It will shut down (the lights switch of for less than half a second) and then come on again. You can actually here the unit click on and off.
The strange part is that it would sometimes still be on or switch itself on without my keys being in the ignition. :confused
The net result is that I am not able to have my alarm on because this drain of power whilst the alarm is activated sets it off...
:crazy
So... what does a man like me do? Well... I gave the side of the dashboard a slap the one day... (not hard.. just a frustrated slap :lol3 ) and it would be fine for the rest of my journey... Well, that was until I drove somewhere else again the next day!
So... I slapped it really hard the one day, (not clever, I know) and then the unit went ballistic and constantly switched on and off till I disconnected the main battery terminal.
After that it reverted back to the intermittent on and off cycle.
No more slapping from me.
Is there a way to get the unit out easily and repair it by opening and perhaps soldering some connection again?
Or would I have to buy a new (and very costly) unit?

Any help would be greatly appreciated.

Cheers
Len
(South Africa)

Im not sure if the cc module is the same in your car as in the e36 but this may go some way to helping you out
http://www.macadamizer.com/bmwfix.html
it may also be worth checking the pins in plug that goes into the back of your module as it sounds more likely that you have a dry soldered connection somewhere.

Thanks Stevo,
will give this a try although my dashboard as well as the actual unit is different and it will be an interesting task to get it out of the car.

But, I will report back once I have it out.
Cheers

So... my report back...
The 740i (E38) Climate Control unit is somewhat different to the 328i, nevertheless...
I removed the unit pretty easily once I realised that I needed to remove a cover to the right of the cup holder by simply pushing up on a clip and gently nudging it forward.

In other words, under the climate control, you have a dual cup holder... To the right of that, is a small cover about two inches long and one inch high. Simply stick your finger underneath that and you will find a clip that you will have to push up on and at the same time gently nudge the cover forward.
It will pop out and you will now be able to stick your finger through the hole - upwards. You will easily be able to gently push the climate control unit out. (No tools were used at all)

I then disconnected all the wires - beautiful clips :) made it really a simply procedure. There were 5 clips in total.

Once on my desk, I easily removed the outer shell to reveal the pcb board.
On the board, I found three caps that looked similar to the unit from the 328i, but managed to find the .47uF cap with the help of a standard voltage tester.
After changing the cap and putting the unit back together, I am happy to report that it worked!

My climate control is good as new and in less that 30 minutes!
Total cost of repair = ZAR17-00 including the electricity needed for the soldering iron :lol
Converted into US Dollar it works out at around $2-42

Thank you Stevo and the Bimmer forums!
Cheers
Len

Hello !!!!
 

Good morning Guys, I am a new member of Bimmer Forum; I am Francesco Cassia and I live in Italy, near Venice (beautiful city). I bought a BMW 728i year '97, color green, great car saloon... I have the same problem with climate control panel; in other words, I replace the .47 CAP (63V) but after seven days the climate is crazy, again :conf. Whats the problem ? Another Capacitor to replace? Thanks Again for your answer, Best Regards...:thanks
p.s: excuse me for my English...not very well !!!! :sweating

Francesco Cassia

Italy