cooling system wiring

Hello again,

On my 300SD I have modified the cooling system wiring for better performance in my hot climate (so calif > 110F) I removed the a/c cutoff sensor above the thermostat, and connected the wire to ground. Next, I installed a 100C Temp switch above the thermostat and wired that with my A/C high pressure switch.
As a result, the fan now comes on >100C or when A/C pressure high.

Is this a safe wiring modification in your opinion guys. Its worked for me for quite some time, but I would like others opinions on it.

I do not have a problem with a mod of this type because some of the A/C systems do need a little help when it is really hot.

My mom and dad have a 190e 2.3. This car will run hot in the summer and all of them will run over 100 so I installed a switch that bridges the wires at the high pressure switch for the A/C. Now mom and dad can turn it on at will.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Thanks for the reply. It works well for me and others might want to consider something like it.

Another nifty feature I added was to replace the coolant tank (the ones the dealers have now have the low coolant switch). I wired the switch to the dash so I now have a low coolant level switch.

It came in handy a few months ago, when amy mono valve leaked and dropped the coolant level.

I too have modified the cooling system on my 92 190E2.6. In warm weather the ac performance is poor at idle and the temp rises to the 100c mark. Instead of waiting for the ac freon switch to activate to turn on the aux fans, I instead installed a relay to power the fans at a low speed via 2 25w .25 ohm resistors and triggered by the deceleration switch on the throttle body through a transistor(high impediece) to activate the above relay. This allows the fan to be on only at idle. Works great and the ac works better than it ever has and the temp stays at 90-90c.