Replacing engine driven fan with electric for better AC
 

Has anyone replaced the engine driven fan on a w126 with an electric puller fan to increase AC performance?

The AC on my 89 300SE was converted to r134a before I bought it. I've further converted to Dura Cool refrigerant which improved it, keeping me nice and cool as long as I'm at highway speeds, but it still struggles to keep the interior really cool when the outside temperature is above 85 and I'm in stop and go traffic. I'm tempted to try it, I just wondered if anyone has any experience with such a conversion and if it did improve AC performance in stop and go traffic.

Thanks.

There already is an electric fan for the A/C condensor, mounted directly on the condensor, which would be more effective than one mounted to the radiator side.

The engine-driven fan is primarily for cooling the engine radiator.

I replaced both the the clutch fan and aux fan with a single electric puller fan from a 90s volvo. The AC is must more efficient especially during stop and go driving in very hot weather. The stock aux fan is worthless. I also use Duracool. If there is enough room between the M103 engine and your radiator, I recommend this fan.
http://190rev.net/forums/showthread.php?t=34975

On my 300E, I bridged the terminals of the temperature sensor connector and got the aux fan to run at high speed. I made a significant difference to the A/C performance and also helped keep the engine temperature down around 85deg.

Very nice tutorial! This is what I was hoping to hear. Would you mind sharing what your high/low side AC pressures are with the Duracool? I keep playing around with mine and can't decide if it's better with the low side around 30 or closer to 45. In the meantime I'll be looking for a fan.

I don't remember exactly because this was more than a year ago. I filled it up through the low side port above the driver's side fender (on a 190e) with a R134 adapter and hose/gauge. The gauge had numbers on it but it was split up into a green, yellow and red section. I filled it up right up to the line between the green and yellow section. I think thats around 40psi.
This is actually similar to what I did on my 2.6 which has 2 side by side auxiliary fans which are much more powerful than single aux fan on the 2.3. If the 300se has a similar 2 aux fan setup, I would give the switch idea a try first.

I wonder if the wiring on that circuit is sized adequately to have the fan running constantly?