temp dial gauge - PeachParts Mercedes-Benz Forum

PILLMANWBA · #1 09-01-2002, 10:58 AM

console temp dial.. can receive heat or ac by turning dial. yet when on runs full blast and does not slow down when set temp is reached. you either freeze or sweat. at moment can only control by hitting low fan speed or cutting off.. did not use to be this way... what gives ??? thanks

ejsharp · #2 09-01-2002, 11:29 AM

I just solved exact same problem. Two things contributed to malfunction. The temp sensor next to my sun roof control was clogged but mainly the problem was in the temperature control module.

The temperature control wheel is attached to a rheostat that controls the temperature settings. The pins from the rheostats (twins sitting side by side... one hot the other cold) can crack at the solder points and become disconnected from the circuit board. If this is the case you will see the crack around the pin where it is soldered to the circuit on the board.

Either resolder the crack or solder a thin wire from the cracked pin to another pin on the same CIRCUIT of the board.

If you are able to do this repair I will tell you how to take the control module out and then disassemble it.

Otherwise buy a new module from parts Shop. Not cheap.

PILLMANWBA · #3 09-01-2002, 01:05 PM

Thanks for your time. How did you unclog the sensor ? Control unit i would have to replace ...

ejsharp · #4 09-01-2002, 01:48 PM

I used a hat pin to pick the caked dust out. There is a hole behind the little grill about the size of a dime. Be carefull not to damage the sensor while cleaning out the hole.

RPM55 · #5 09-01-2002, 09:00 PM

You can also use a vacuum cleaner to suck the dust from the in car temp sensor.

RSH · #6 09-01-2002, 10:03 PM

Are you talking about when in full auto mode or are you useing the fan/blower buttons above and below the autom button, when useing the buttons above and below the autom button the fan/blower will continually run and not shutoff even when the desired temp is reached. If you are useing full auto mode and the fan/blower speed is not changing then you may have a temp sensor problem or temp dial problem.