Bosch Temperaturregler Repair

What I thought was monovalve problems turned out to be an electronic control box hidden behind the glove box. My heat was erratic, hot, cold, different vent temps at idle than at highway speeds I had been chasing for a long time.

I cannot stress how incredible the community around our W123s is, Joe emailed me with his findings and success repairing his climate regulator, I checked mine out and sure enough, failed capacitors. A quick soldering job and my climate control is fully automatic and varies temperature and fan speed like it was meant to rather than being an on or off binary type system that it had been.

There are several variations to this box, if you have a revision that isn’t listed here, please contact us, I would appreciate your help to have the most complete and comprehensive free resource for repairing these.

To get to your climate box you will need to remove the glove box liner and unscrew the phillips head screw holding the box in place:

Once you get the box out, you can pry apart locking tabs and remove the circuit board

The circuit board in my car looked like this:

This image has an empty alt attribute; its file name is Topside-1024x700.jpg

You will have to carefully desolder and remove each of these capacitors and replace them with new ones either purchased in bulk like I did, or you can try out our brand new store:

Please keep in mind the store function is a new idea, we will see how it works, there may be some issues initially, please bear with us while we try our best to get your orders taken care of!

If you’ve got a board like this, then you will need either one of the kits I sell:

What you need if you choose not to buy a kit:
1x 470uF cap:
1x 22uF cap:
2x 33uF cap:
2x 47uF cap:
3x 100uF cap:
Soldering iron:
Solder wick:
3/4 Split loom for temp sensor:

Documentation to print out:

Leave a Reply

Your email address will not be published. Required fields are marked *