91° and 99° temp switch on Radiator UPDATE

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Joe Boston
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Joined: Sun Nov 27, 2016 12:11 pm
Location: Winchester, MA

91° and 99° temp switch on Radiator UPDATE

Post by Joe Boston »

Doe anyone know the 2 temp switches part #'s on the radiator.
I am not able to locate them on the realoem.com
Also is the lower Temp switch 91° (which is mostly use to drain the radiator) and the one about mid height on radiator is 99°. I believe the PO used an incorrect relay that could have burnt out the switch and was causing drainage of the battery.
if anyone has any insight or have replaced these in the past.
The problem I am having is the AUX fan doesn't turn on when the temp gauge on the car is slightly past the mid point. Engine runs hotter when using the A/C. When i put a jumper wire the to lower switch then the fan turns on, or if i jump on the rely points 30 & 87 fan runs.
This test would rule out the resistor on the fan.

I was finally able to find the part # on the aux fan temp switch the upper one is 61 311 364 273 --99°
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the lower aux fan temp switch of 61 311 364 72--91°

Image

hope this helps
1980 E12 Ascatgrau 5 speed
2001 E38 740 Black
2012 F12 650 IC black
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Robert Bondi
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Location: Austin, TX

Post by Robert Bondi »

If you want the aux fan to come on near midpoint on the temp gauge, you actually need the 82C version of that same switch. I've calibrated midpoint on the T gauge to be about 80C. The 82C switch part number might be in my cooling system FAQ. If not, I've sourced it
through places like BavAuto or BMP. In normal operation, aux fan should be triggered by AC compressor regardless of coolant temperature.
Robert
77 530i
77 Euro 528
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Joe Boston
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Joined: Sun Nov 27, 2016 12:11 pm
Location: Winchester, MA

Post by Joe Boston »

Robert Bondi wrote:If you want the aux fan to come on near midpoint on the temp gauge, you actually need the 82C version of that same switch. I've calibrated midpoint on the T gauge to be about 80C. The 82C switch part number might be in my cooling system FAQ. If not, I've sourced it
through places like BavAuto or BMP. In normal operation, aux fan should be triggered by AC compressor regardless of coolant temperature.
After ordering the temp switch, what arrived was an 82° temp switch, When the Aux fan kicks in my Temp gauge is at mid point.

All good. thanks for the tip
1980 E12 Ascatgrau 5 speed
2001 E38 740 Black
2012 F12 650 IC black
User avatar
Robert Bondi
Posts: 403
Joined: Sun Jan 11, 2009 12:33 am
Location: Austin, TX

Post by Robert Bondi »

Great. Glad it worked for you.
Robert
77 530i
77 Euro 528
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