This was a good idea guys, last year I had a problem with my Tempmatic Climate Control unit too but what I did was use a stop watch, turkey thermometer, the wifeís hair dryer and it worked for me:
1. On my 87 190E 2.3 and I think most Mercedes-Benz the Tempmatic Climate Control unit if itís malfunctioning it goes into an override function.
2. This symptom is a non response from the pushbutton unit (the air is hot and it comes out of ALL vents no matter what button you push) and only the fan speed works.
3. It may seems to go on and off intermittently but itís actually not, it is timed in seconds. There could be five possible things wrong with the unit so five different time sequences.
4. In my case it was the outside temperature sensor because after one clicking noise from the relay the fan will go on for 20 seconds pause for four then on another 20 and so on.
5. In youalls case (if with the same fault) with the tool you will get 10 blinks every 20 seconds and so on.
6. Anyways the 20 seconds point me to the outside temperature sensor I disconnect it from the vehicle to ohmed it out but didnít get a good study reading, what the fault was the solder became weak at the pins so I resoldered it and tested it again, got study reading!.
7. The way Iíd tested for correct output was put it in the freezer for about 5 minutes, took it out and measure the ohms at the same time put my turkey thermometer next to it to read the temperature, use the wifeís hair dryer to make it hotter and raise the temperature, the ohm readings were correct at all temperatures, installed it back into the vehicle, the system worked fine after that.
Thai GI sends...