AC/Heater Blower Motor Transistor.

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ilouie
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AC/Heater Blower Motor Transistor.

Post by ilouie »

Hi, I have an issue in which I have not been able to find a solution for it. My 85 E24 has the AC Blower Motor gone. The only one working is the Heater Motor inside the Bonnet. My problem is that the Heater Blower Motor only works on high, which I pin pointed it to the Transistor right behind it. Now, I took the Heater Motor out and replaced it with the AC Motor, which it works but, the fan also works on high only. My question is, would I have to replace both, Heater and AC Transistors, or is it normally just the Heater Motor Transistor?. Thanks in advance.
baders
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Re: AC/Heater Blower Motor Transistor.

Post by baders »

The problem is the heater blower transistor, but you should check and probably replace both.
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songzunhuang
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Re: AC/Heater Blower Motor Transistor.

Post by songzunhuang »

baders wrote: Wed Oct 25, 2017 12:26 am The problem is the heater blower transistor, but you should check and probably replace both.
This is a very inexpensive part. I paid $2.99 USD for each of mine. You have to be handy with soldering and desoldering, but it's not hard.
Here's a picture of when I did my outside blower motor controller. You'll need a stubby flathead screwdriver to make it easy to remove.
Transistor for blower motor.
Transistor for blower motor.
Screen Shot 2017-10-25 at 5.03.17 PM.png (1.16 MiB) Viewed 5142 times
The one for the inside blower is a bit harder to get to. You'll have to remove the center console and get into the Evap Core box.
Here you can see it in the lower left of the picture next to the Expansion valve for the AC. Ugh.
Transistor for AC blower. Lower left.
Transistor for AC blower. Lower left.
Screen Shot 2017-10-25 at 5.08.36 PM.png (1.31 MiB) Viewed 5142 times
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Song Huang
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JCS
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Re: AC/Heater Blower Motor Transistor.

Post by JCS »

ilouie,

Here is a link to the A/C transistor.

http://bigcoupe.com/phpBB3/viewtopic.php?f=2&t=28758
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603racing
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Re: AC/Heater Blower Motor Transistor.

Post by 603racing »

I'm having some internet navigation issues at the moment, otherwise I would find the exact info, but.........

I replace mine with a transistor from Radio Shack. MUCH cheaper than buying the whole part from a parts supplier or BMW. There is a whole write up on it somewhere that is very helpful. Way more helpful than my post. :)
'85 635csi - Dark Shark
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