S-Class (W140) 1991-1999: 300 SD, S 350TD, 300 SE 2.8, S280, 300 SE 3.2, 300 SEL 3.2, S320, S320L, 400 SE, S420, 400 SEL, S420L, 500 SE, S500, 500 SEL, S500L, 600 SE, S600, 600 SEL, S600L, 500 SEC, 600 SEC

Heater/AC blower W140

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Old Nov 4, 2019 | 08:12 AM
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W140 400SEL 1992
Angry Heater/AC blower W140

Hi all

I need your help my 91 400 SEL ahs suddenly decided that the blower motor will keep running at full speed even when the car is switched off and the keys out of the ignition.


Another post suggested to replace the K30 relay, so I bought one only to discover that the relay box in my car is nothing like the one above which is illustrated on this site!
My relay box has only got two large relays (lights and something else) and 4 small ones, have pulled all of them and it makes no difference the blower motor still runs continuously I have also replaced the resistor on top of the motor which has made no difference.

Problem is here in Western Australia we are coming into summer with temperatures outside in the mid to high 30 degrees C, so the car can easily hit 40 degrees inside!

Can anyone suggest where the relay that controls the blower motor is located?

Regards
John
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