hi, i'm tired of my compressor cutting out while it's still not cold. how do i perform a mod to put a switch on the dash such that i can turn on/off the compressor at will? after all, it's practically hot all the time where i am...

understand from a prev post that there is some kind of valve/relay that is linked to the evaporator? will replacing that help, and what does it look like? my w123's a/c is a non-climate control type... thanks.

roland

There probably isn't a more costly way of dealing with your problem. I don't get it. If its broke why don't you fix it. Since you haven't specified the year or model or in your case the A/C version, its hard to make guesses.

I'm relatively sure that a rig such as you want will cost more to have done than a proper diagnosis.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

If you know that the evap temp regulator is not regulating properly, just replace it. (IF it is the problem)

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Benzmac:
Donnie Drummonds
300E
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

gosh, thanks steve, for the timely advice.

now if anyone could help me with this - what does the evap temp gauge look like and where is it? i can't find it in my chilton's book.

the compressor sometimes "kicks out" while it still isn't cold, and "kicks in" again, and it especially likes to kick out during idle though not exclusively. is this eva temp gauge expensive? what else are possible causes of this? a bad compressor clutch?

my 123 is a M115 200 - 1979.

Being a entry model 123 chassis I presume it has manual A/C not Climate Control. From the year this would mean a simple "ranco" style evaporator temperature switch. This is the same type switch with gas filled capillary tube into evep that works on old refrigerators/water coolers/Coke machines. Power comes in and is switched to the compressor through this switch which in MBs case is a fixed (non operator adjustable) temp switch. It is located behind the glove box.

Power comes through the blower switch I think and goes from the evap switch through the low pressure switch. Many places for poor circuits.

i have removed the glove box, but can't seem to find the evap temp switch. what does it look like?

given the fact that it is a "manual" a/c, it wouldn't have an aircon temp sensor right?

also, does having not enough "gas" in the a/c system affect when the compressor cuts in?

thanks.