A/C fan control switch

[MORRIE]

It's always something. When I turned the fan control switch on nothing happens. However when I turn it onto the highest speed, it works. After several attempts, same issue. I assume the switch needs replacing. Can I gain access to the switch on the HVAC unit through the radio opening?? Please advise.

[delvec]

Its most likely your fan resistor. Unfortunately, it's located on the blower motor hosing under the windshield cowl. The contacts may need to be cleaned or the resistor needs to be replaced.

[Vintage42]

The low speeds use the resistor and the high speed bypasses it.
Blower circuit.jpg

Resistor-changing DIYs:
https://www.bimmerforums.com/forum/s...on-4-write-up-)
https://www.bmwcca.org/roundel/hey-k...ed-resistor-z3

[MORRIE]

You are correct Delvec. Thanks

[MORRIE]

Vintage you have done it again...posted threads that are extremely helpful. Rob's thread is amazing...details w/photos. I wonder how much the BMW dealer would have charged for this DIY. Thanks much, man!

[Vintage42]

... I wonder how much the BMW dealer would have charged...

And what if he had first gone for the switch in the console LOL.

[Mr Bingley]

This might explain your odd intermittent AC issue--if the resistor is failing and you drive around with the AC on and the fan in positions 1 through 3, the evaporator will eventually ice up, and, when the fan does blow, only warm air will come out; once the evap defrosts, cold air will blow again. (Ok, I think I pulled that off in one sentence for punctuation geeks out there).

[Vintage42]

... if you had a leak you would NOT go from cold air to hot back to cold... .

This might explain your odd intermittent AC issue--if the resistor is failing and you drive around with the AC on and the fan in positions 1 through 3, the evaporator will eventually ice up, and, when the fan does blow, only warm air will come out; once the evap defrosts, cold air will blow again...

Neat cross-thread deduction!

[MORRIE]

Here is the little culprit that caused the blower not to work properly. Received its replacement last week. I had to order a wiper arm puller to remove the wiper arms to gain access to the blower where the resister pack is housed. Now the blower works on all speeds. Just another BMW Z3 learning experience. I wonder what's next???

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[MORRIE]

Neat cross-thread deduction!

Excellent deduction Ralph.

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[Randy Forbes]

Here is the little culprit that caused the blower not to work properly. Received its replacement last week. I had to order a wiper arm puller to remove the wiper arms to gain access to the blower where the resister pack is housed. Now the blower works on all speeds. Just another BMW Z3 learning experience. I wonder what's next???



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The takeaway here being that you probably won't have to wait long to find out...

[Mr Bingley]

Excellent deduction Ralph.

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Deduction shmedudtion--how about that punctuation.