High speed fan setting for HVAC not working 1990 300SE

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Nov 11, 2004 | 01:43 PM
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Hello All,
I have a 1990 300SE with 236,000 miles and the high speed fan for AC and heater does not work.
I took apart the HVAC controller and re-soldered all the joints. Still not working. Any ideas of what the problem could be?
Thanks in advance
Dan
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Nov 11, 2004 | 03:22 PM
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Check the blower motor regulator, located in the fresh air stream of the heater box.
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Nov 11, 2004 | 04:35 PM
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Jer, Thanks for the reply
what is the blower motor regulator? Is it electrical or mechanical? Similar to a relay?
Anyone know how to get to it on a 126 car?

Thanks
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Nov 11, 2004 | 04:50 PM
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It is a transistorised controller for fan speed regulation. You get to it through the fresh air grille under the windshield (at least on a 124).
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Nov 11, 2004 | 05:27 PM
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So I have to take out the dash pad?
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Nov 11, 2004 | 05:29 PM
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No. The fresh air grille is outside, near the wiper transmission.
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Nov 11, 2004 | 05:31 PM
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right in front of the wiper trans. area, in the engine compartment?
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Nov 11, 2004 | 05:48 PM
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Not in the engine compartment. Under the windshield. You can't miss it.
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Tags 1990, 300se, 91, ac, blower, doesnt, fan, high, hvac, inoperetiv, regulator, speed, w126, work, working
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