Hello,
This is my first post,
I've been lurking around here for awhile now,
learning a ton about my cars.
Thanks to all for great Info.

Anyway, I broke this off the end of a wire where it was plugged on at the rear of what I think is the thermostat housing, there's a vacuum switch right next to it, on the passenger side of the valve cover at the front, on my '83 300DT. auxiliary fan sensor?

It has 2 part numbers on it, one at each end,
0095451428 on the top, and
0085452028 on the bottom.

My parts guy couldn't find it.

It seems kind of elaborate for just a plug end.
Wondering if it has some other function as I need to replace it.

thanks,
Brian

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'85 300DT 170K
'99 R1100RS 63K
'84 300DT 126K ate her own camshaft
'83 300DT 252K executed by non-driver
'68 F-100 138K sold (why?)

Yes, it's just a fancy plug end. The temperature sensor it plugs onto is for (I think) the climate control system -- it tells the CCU that the coolant is warm and that the blower can start running. Prevents the system from blowing cold air onto occupants on cold winter days (heaven forbid!).

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

oh,
thanks.
the car does seem to run fine without it.

__________________
'85 300DT 170K
'99 R1100RS 63K
'84 300DT 126K ate her own camshaft
'83 300DT 252K executed by non-driver
'68 F-100 138K sold (why?)

It should. The switch has nothing to do with the engine operation, its only for human comfort.

You could just install a ring terminal on the wire and attach it to ground. That way, your cabin blower fan will work regardless of engine temperature.


The aux fan operates solely on the basis of a/c refrigerant temperature, not engine temp.

It's actually a switch, not a sensor. It's open when cold, closed above approx 100*F. It provides a ground which permits actuation of the K-3 relay in the CCU, thereby powering the blower. MB calls it the "cold engine lockout switch."

Thanks, that's what I'll do.

__________________
'85 300DT 170K
'99 R1100RS 63K
'84 300DT 126K ate her own camshaft
'83 300DT 252K executed by non-driver
'68 F-100 138K sold (why?)

Since there are two part numbers, will the inside separate from the outside, allowing the wire to be reattachted after it has broken off?

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85 300D 75K Anthracite Grey 0-60 in 13 seconds **For Sale**
84 300D 333K Black (The Velveteen Rabbit) 0-60 in 14 seconds
00 Toyota Sienna 208K (Sold)
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98 Ford Taurus 100K (Gertie - Was Grandma's - drove it to church and shopping - really) Daughter's car now.
30 Model A Ford 2 Door Sedan (Sold) 0-60 in . . . Never reached 60