I'm having problems getting to all the solder joints on my 300E push button unit.

The unit has a bottom plate, which comes off fairly easily and exposes most of the solder joints.

What I can't figure out is how to get the front face off to get to the other solder joints, like the fan speed control button area. I see 4 clips, but I think the front 5 push buttons are keeping it on.

Do these buttons pop off? Anyone know a trick to completely disassemle the unit?

Thanks so much for any advice...

Here's what I have apart so far

You do have to pop the buttons off gently - one at a time. Watch how they come off and organize a storage method so you get them back on correctly.

Having said that, and having completely disassembled my 1987 300D ACC, you may want to stop taking the thing apart right where you are now - and just resolder the joints you can see. What you see right now is the vast majority of solder joints. Its just the one circuit board.

What are the symptoms of the problem you are having? Mine was that the AC compressor came on in ECONOMY mode, and the fan would still run in OFF mode. I could actually see a bad solder joint in the circuit board you show. It could have been fixed with only taking off the bottom cover. So don't tear the thing down any further than you have too......

Ken300D

Ken:

Thanks for the info

I needed to go further in to get to the fan speed controls -- I resoldered those and voila, all the fan controls/speeds work like they're supposed to.

BUT

I have a small problem. When I first started car everything was fine -- hot and cold air were adjustable. Second startup, now all I get is hot air. All of the vacuum pumps are working as air is being divererted as it's supposed to, but nothing but hot on any setting.

Weird.

I guess I fixed one solder and screwed up another. Ugh.