Just over the weekend, my climate control unit (1990 300sl 24v) malfunctions. There are 5 lights permanently on and will not respond to any amount of button pushing. The little temperature read out on the top left also shows illegible characters.

Has anyone else suffered from this ?

it malfunctioned during the longest continuous trip of about 90 miles, the temperature in the cabin went up to its highest, which i am sure is fine for winter - but summer is a comin' !!!!

Is the vehicle ok to still use ?

is it as simple as a unit swap out or more indepth ?

regards

simon

1990 300SL 24v

 

it is already due to weak electronic parts inside the climate control.

resistors are know to react on temperature changes and the value differs from hot to cold.

the LCD display also reacts to heat.

 

many thanks for the input, do you think it could be resolved by a straight swap out of unit or is the temperature in the cabin is not being regulated properly ?

I have found a local company who have agreed to check the circuit board / components, with the possibility of re-soldering all joints to eliminate dry joint failure.

will keep the forum informed.

however - if anyone else can add input - the more the merrier !!!!

many thanks to all

regards

simon

1990 300SL 24v

remember - "if you dont ask - you don't get" and

"its easier to get a pardon than permission from your partner"

 

Swap out is simple process - remove radio from console, Push Climate control unit from back and slide unit out.
There will be (2) wiring harnesses attached to top of control unit. To disconnect wire harnesses there are simple
tabs that squeeze together to attach and spread apart to disconnect. There are several places that sell re-manufactured units. Or you can buy used units from Martinito motors. I have purchased several large ticket item from them and are great to work with. you should be able to find them on ebay motors.
Rich

 

1990 300sl climate control unit 129 830 02 85

I had minor circuit board repairs done, dry joint check, but no difference, the unit is still locked, and when connected the air con fans stay on.

Without trying a new part, I am lost as to what to try next. SUGGESTIONS ????

does anyone know who might be able to supply replacement / exchange / repair unit in the UK, the previous post mentions MARTINTO, but postage cost is the same as the unit to the UK

regards

simon