ACC stuck in Low fan still blows heat
 

Hi,

Yesterday my 1988 560 sel's Automatic Climate Control is not working. It seems like it is stuck in low fan but some heat is blowing. If you turn it off it still runs. If you put it in defrost, it stays the same. No changes when any button is hit. Also the recirculate switch is not working also.

Is it the push button control unit or the relay. Does it goe to this mode if the relay is blown.


fenez@dryden.net

Thanks in advance...

Fan runs at all times
 

If you click the high speed button, does it go in high?
(even though the off button is pushed in)
Does your A/C compressor engages by itself?
(even though the off button is pushed in or you have it in economy mode)
Do you hear a relay clicking on and off somewhere behind the cluster and the fan is supposed to be off?
If you have any or a combination of the above mentioned symptons try taking the CCU out and resoldering the contacts to the on/off switch. I did them all for safety, now it works like a charm

Well,

I pulled out the climate control buttons and removed the circuit board. Now, get this as I pulled the radio out I thought I would check the to see if the fan started to work so I turned on the key. Sure enough it did. So I continued to pull out the the acc control unit. Then I turned the key on again just before I unplugged it. And then it didn't work. So I unplugged it and put it on the bench and started to take the board out. I noticed a hot spot by left bottom corner on the circuit board. It was a diode. I checked it and it was still good. So I resoldered the connections and reassembled it. It still doesn't work but I did for a second. Boggles me. I did also resolder the on and off buttons but they looked good to me.


Previous post ,

Nope you can push any button and the thing stays in slow fan and heat is on. A|C does not work either. Recirc, does not work either.


I think I need a new push button control unit.... If I was working around it and it started to work. Something must be funny in there.

Oh yah, I forgot to mention,

I took the car for a ride and heat is blowing through every duct. The direct vents, defrost, floor, door heat. But fan is on low and again when you push the ACC buttons nothing changes in the way of directional flow of air.

This is alright for now, it is cold out, but when it warms up, it is gonna suck.

Anybody else come across a problem like this.....