Hello All:
Just finished getting all my parts shipped in for my coolant flush for my '85 190E 2.3 (kudos to the PartsShop for the ease in ordering and fast shipment of the parts -- please remember to support this website with parts orders, members).
After reading a variety of posts on coolant flushes/heat issues via the search feature - I noted that a variety of heat problems stem from fan problems. So, I went to check operation of my aux fan by turning on the A/C (I haven't had to run it yet, this season). Well, the Aux fan refused to come on with the A/C. I checked the fuse and it was blown. I replaced it and the Aux fan still won't kick in with the A/C.
At this point, I noticed that on the bundle of three wires running into the block sensor next to my thermostat - a red wire (formerly soldered into the top of the sensor) had come ajar. The wire runs into the black fuse/switch box that sits to the front of my large fusebox. Holding the wire against the place on the sensor it had appeared to come dislodged from makes no change in the fan...sides, I assume that is the switch to tell the fan to kick in at high temps, not at A/C compressor activation - or might be unrelated.
A W201 service manual CD is in the mail, a belated b-day gift from a friend. Any advice before it arrives on this? I would love to get this settled asap, so I can get back to flushing the coolant system...which I will not begin until I get the aux fan working again.
Thanks all,

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John J. Meadows
'85 190E 2.3L 96k mi.
My first M-B, not my last.

The fan will not come on as soon as the A/C is turned on...You can check it with a simple procedure. Just turn on the key. Next locate the red or green switch on the side of the drier bottle (located behind the driver's side headlight) and bridge the wires that are there. Do not unplug them, just jump a wire across. The fan should run, if so, you have checked 1/2 of the circuit. The other half is related to the operational temperature of the engine.

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Benzmac,
Thanks for the reply. I did bridge the wires on the red switch on the drier this weekend and the fan came on like clockwork. Trouble is, with the exception of that moment, I have never heard the aux fan kick in...period. Of course, that might have something to do with the blown fuse that I replaced. Heh.

How long after turning on the A/C should the aux fan engage? Driving the car with A/C on for 10-15 minutes did not cause the aux fan to engage, even with engine temps in the 90-100C range.

Thanks very much,


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John J. Meadows
'85 190E 2.3L 96k mi.
My first M-B, not my last.