# Another Final Stage Resistor Bites The Dust



## EdCT (Mar 14, 2002)

Thanks to the folks here at Bimmerfest, I was able to prepare myself for the "final stage resistor" bit.

My climate control began acting up so I did a quick search here and lo and behold, lots of folks with the same problem (or subset thereof) which required a final stage resistor.

My car, a Y2k 323i, has only 30k on it, but the cc failed nonetheless.

I was able to describe the symptoms and possibly the problem to my service writer at the dealership. He was quite impressed! (thanks guys).

Anyway, it was covered under warranty.

Seems this is a common problem.

Ed


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## erguy63 (Sep 12, 2004)

It is quite common on later 3 series BMW (5-6 out of 10 per one dealership). I just fixed my 96 328i final stage resistor by myself. Cost of the parts is about $110.


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## haissams (Oct 16, 2004)

Mine is a 1993 BMW 325i (E36). My Climate Control system has been acting up. It's not only the air conditioner that acts up, it's also the defrost, and air recycle buttons. For example, when the defrost works, the AC works. They go on and off in unison. Could this still be the the final stage resistor? I've already changed the climate control unit that's just near the stereo behind the panel, an dalso changed the blower (heater) resistor - all done at a mechanic shop but no fix yet. I took it to the dealer and they also re-changed the climate control unit too but no fix? Has anyone experience this where the AC and the defrost, and the air recycle functions are all erratic (i.e. more often they don't work!!)

Thanks,

Sam


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## streetk14 (Oct 16, 2004)

sam, can you better decribe to me what is happening? Are you saying that the blower motor is cutting out at times? If so, it is most likely a final stage resistor, or the motor itself. Replacing the motor is a headache, and a lot of $$$ if you are going to pay someone to do it.


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## EdCT (Mar 14, 2002)

haissams said:


> Mine is a 1993 BMW 325i (E36). My Climate Control system has been acting up. It's not only the air conditioner that acts up, it's also the defrost, and air recycle buttons. For example, when the defrost works, the AC works. They go on and off in unison. Could this still be the the final stage resistor? I've already changed the climate control unit that's just near the stereo behind the panel, an dalso changed the blower (heater) resistor - all done at a mechanic shop but no fix yet. I took it to the dealer and they also re-changed the climate control unit too but no fix? Has anyone experience this where the AC and the defrost, and the air recycle functions are all erratic (i.e. more often they don't work!!)
> 
> Thanks,
> 
> Sam


As I recall, mine just had a mind of its own:

It would often keep running for several seconds after the car was shut down.

It also would speed way up, then drift down to nearly nothing; a real schitzo.

The fix was the resistor.

Ed


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## haissams (Oct 16, 2004)

*1993 325i - Climate Control Unit*

Well, Mine has the analog controls, being a 1993 325i. It has (3) buttons, one each for the AC, defrost, and the last is the one that recycles the air within the car. Mostly, they all stopped working. For example, when I push the AC button the AC does not activate (but does so once in a while.). The same goes for the rear defrost. I push the button, and the defrost light does not turn on and the deforst function is dead which could be be an inconvenience while driving... However, If the defrost happens to work, the AC will work but will turn off if I reduce fan speed... The opposite is true too in that if AC works, defrost works too but may shut off on its own! I noticed that that when I turn on the fan, some air will come out but now very little air! However, if the AC happens to work and activate when I try turn it on, the fan speed will be higher and fan blows air as it should.... Like I said I have already had the heater resitor and the climate control unit replaced. The climate control unit was changed twice (one at a mechnic shop and another at the dealer's). The Dealer diagnosed teh problem wrong (theought climate control unit) and they could not fix it! I did buy the final stage resistor online (P/N) 64 11 8 380 580 but hav enot yet had it installed at my friend's repair shop. Any input will be greatly appreciated. Sam



streetk14 said:


> sam, can you better decribe to me what is happening? Are you saying that the blower motor is cutting out at times? If so, it is most likely a final stage resistor, or the motor itself. Replacing the motor is a headache, and a lot of $$$ if you are going to pay someone to do it.


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## Artslinger (Sep 2, 2002)

Mine is going I'm having replaced in a couple of weeks.


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## johnf (Sep 16, 2003)

I have silly question: over the last few years, has BMW gone back to using a resistor pack to control the fan speed rather than the solid state PWM stage you find in the older IHKA systems?


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## jkbe30m3 (Oct 18, 2004)

*what does this part look like*

I need to give this resistor a shot because nothing else is helping my problem. Were is it, and how do I replace it. Pictures would be awesome.

I am new to the bmw thing. But my M3 has been nothing but problems since I purchased it. I have an 1988 Rx-7 turbo that works better than this car has so far.

Please help me I have intermittent heat and it is 10 degrees out side.


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## HW (Dec 24, 2001)

erguy63 said:


> It is quite common on later 3 series BMW (5-6 out of 10 per one dealership). I just fixed my 96 328i final stage resistor by myself. Cost of the parts is about $110.


to me a resistor is a $0.03 piece. :dunno: what does this final stage resistor for $110 look like?


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## jpherit (Dec 22, 2001)

*final stage resitor gone*



EdCT said:


> Thanks to the folks here at Bimmerfest, I was able to prepare myself for the "final stage resistor" bit.
> 
> My climate control began acting up so I did a quick search here and lo and behold, lots of folks with the same problem (or subset thereof) which required a final stage resistor.
> 
> ...


I lost my final stage resistor 3 weeks ago. (2001, 325i, 31k miles) Replaced on warranty. Dealer agreed with my diagnosis of problem. Thanks everybody! The fan had a mind of its own. I shure hope they have fixed the problem. While I am very happy with my 325i, I don't think their electics are as reliable as they should be. (I also lost the engine fan early on. apparently that problem has ben fixed as I have had no problems with the Bosch fan. It was a Siemens unit that failed.)


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## BlackChrome (Nov 16, 2003)

HW said:


> to me a resistor is a $0.03 piece. :dunno: what does this final stage resistor for $110 look like?


Courtesy of sycE46 on e46fanatics









BTW, my buddy at the local BMW parts department told me that the current resister for the e46 is an update of another update...  Let's hope mine doesn't crap out again!


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## markl53 (Nov 4, 2004)

haissams said:


> ..For example, when the defrost works, the AC works. They go on and off in unison. Could this still be the the final stage resistor? Thanks,
> 
> Sam


Is it possible you never noticed the AC going on with the defrost mode? In most cars, this is the case to speed up clearing the windshield by dehumidifying the air. In some cars, you won't see the AC light come on but you can hear the compressor kick on. In other cars the AC light will show up if it wasn't already on. When you turn off the defrost, the AC button should go back to the mode it was in before (i.e. off or on). Actually, I haven't yet used the defrost mode in my new 330i, but I'm assuming it works like most other cars I've owned.


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## Andre Yew (Jan 3, 2002)

I had mine replaced this summer after a few months of slow deterioration. My dealer service writer claims that they don't fail after being replaced once.

--Andre


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## Artslinger (Sep 2, 2002)

Andre Yew said:


> I had mine replaced this summer after a few months of slow deterioration. My dealer service writer claims that they don't fail after being replaced once.
> 
> --Andre


I hope not... had mine replaced in my 325 last month.


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## HW (Dec 24, 2001)

BlackChrome said:


> Courtesy of sycE46 on e46fanatics
> 
> 
> 
> ...


at $110 that still price gouging. :tsk:


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## haissams (Oct 16, 2004)

*Final Stage resistor - E36*



erguy63 said:


> It is quite common on later 3 series BMW (5-6 out of 10 per one dealership). I just fixed my 96 328i final stage resistor by myself. Cost of the parts is about $110.


Hello! I have a 1993 325i (E36). I've had problems with climate control not working (once in a blue moon it does work)! The climate control includes the rear defrost and the A/C! It's an electrila problem for sure. I changed the climate control panel and also the heater motor resistor but those did not fix it! Then, I bought a final-stage resistor new for $110 (p/n 64 11 8 380 580) but my friendly mechanic could not find where it would be in the car so to replace it! Do you know if a 1993 E36 has a final-stage resistor? It seems to be confused with the heater motor resistor. If so, where inside the car would I find the final-stage resistor? Thanks, Sam


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