Can A Two-Pin Coolant Temperature Switch Handle Full Auxiliary Fan Power Through It? - PeachParts Mercedes-Benz Forum

Squiggle Dog · #1 05-07-2018, 09:11 PM

Quote:

Originally Posted by marco5

IMO - You won't really gain a cooling benefit from the aux fan running full bore and you may wear it out quick with it running when the compressor is on. It's meant to power on when the drier hits a certain temp, and when that temp is hit, in order to protect the system it will lower the pressure by turning on either low or high speed. Maybe keep the temp. switch OEM setup? Just a thought but they designed it this way for a reason!

From what I've read, it seems running the fan all the time the compressor is running is the way to go as the refrigerant temperature switch is seen as unreliable and by the time it turns on the auxiliary fan, it's already too late and has to "catch up".

They way it was designed may be the best way, but there is a possibility it's not. The early W116s didn't even have pressure switches, but over the years designs change based on new findings. It's been claimed that a big improvement in air conditioning performance has been made by wiring the auxiliary fan so it runs with the compressor.

Whatever it is, I want the most efficient system that I can practically make. So, I'm just trying to read all I can to come up with the best solution.

ROLLGUY · #2 05-07-2018, 09:21 PM

Quote:

Originally Posted by Squiggle Dog

From what I've read, it seems running the fan all the time the compressor is running is the way to go as the refrigerant temperature switch is seen as unreliable and by the time it turns on the auxiliary fan, it's already too late and has to "catch up".

This is absolutely the case, and even many newer cars have this feature.