My 93 300D gets hot at stop lights, the fan clutch was worn out and I've replaced it and it takes a little longer for the temp to creep up, I'm looking for a way to test the electric fans without having to get the motor hot

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1993 MB 300D 245K died.

Do you mean the aux fan for the AC? I just did this test on my 85 300D before wiring up a manual Aux fan switch. My aux fan is powered via a relay controlled by a temperature switch on the receiver dryer. With key on, if I short the temp switch's black and brown (ground) wires together, the aux fan comes on. Your's may be similar.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

on the reciever dryer there is a pair of electric switches. jump the wires to the one with the leads built in, and the fans will run in low speed if your resister is not blown.

of course, you could test the motors by pulling power, and jumping it to a battery, but I'm guessing you want to verify the fans work at temp...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

You can also check the operation the freon temperature switch by placing it in pan of hot water and see if the fan comes on. I think the temp is about 135-140. Don't remember for sure but you find that.

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Baton Rouge, LA
1977 300D Non-Turbo

It is easy on the OM60x. There is a 3 prong plug thermostat on top of the engine, on the coolant hose. Remove the 2 wires harness and short the harness 2 connectors. The Aux fan should come on.

I wire a switch there in parallel with the hardness to turn on the Aux fan when I go thru desert. Just in case.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Thanks all, fixed it, works great, wiring issue

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1993 MB 300D 245K died.