Think I found my no heat problem........

[dsan]

I finally had the chance to pull the ccu this past weekend to take a look at whats going on. When I bought the car, the previous owner had been fighting to get the heat fixed for me for months but unfortunately kept running into walls getting the ccu rebuilt, or more specifically the cabin air temp sensor replaced. When the weather broke, I had the chance to pick up the car and now it's my turn to try to fix it up

Right now, I have cool air and I believe a/c (too cold lately to check the air temp but do hear the compressor kicking in when the a/c is engaged) BUT as soon as I turn the temp dial up from max cold the fan kicks off. I found a video on youtube that shows exactly what I'm dealing with

【 AC Problem 】 Porsche 964 Blower fan does not working when hot air. - YouTube

(not my video)

but mine cuts off with the a/c button on or off. After reading through Tori Bergvills' multiple times, I opened the ccu and found that what I believe is the thermistor or sensor seems to be gone. My question for you guys is if anyone knows where I could pick one up? I've checked through pelican, jim ellis and plenty of other sites without any luck. Is this part sourced separate? Or do I need to pick up a new/rebuilt ccu? Obviously my wallet would prefer the just the sensor/thermistor or even finding a used ccu. If not, does anyone have nay personal recommendations on where to get the ccu rebuilt? Or does anyone else have any other recommendations?

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Short version for the ADHD- Does anyone know where to pick up the missing thermistor/sensor in the above picture
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[crg53]

I would try to contact LorenB at THIS address.

[ToreB]

You have at least two problems with your heating system. Rear fan and the interior temp sensor.
Fan speed: You are describing a typical rear fan problem scenario, when the rear fan is not working properly, the front fans are shut down. The rear fan is supposed to run when you turn the temp control up. See my DIY for details on this.

Interior temp sensor: I would think the sensor is there, but the leads from it has been ripped off the PCB. That's an easy fix with a soldering iron. There's two solder pads on the short end of the PCB where these two wire ends shall be connected. See the pic below how it's supposed to look like.
Cheers,
Tore

[dsan]

Thank you gentlemen

I was hoping to try to give it a go at fixing it myself first before I contact LorenB just because I don't want to beg for help while he gets paid to repair them. Don't want "take food out of his mouth" sort of speak. But if I can't get it squared away, I will definitely be contacting him for a rebuild.

Tore, I've been studying your pages for the last few days. Thank you so much for putting something like that together to help us layman's out
I opened the PCB up further and the temp sensor doesn't appear to be there. Now it was sent out for a rebuild before I bought the car so maybe it was misplaced? I checked from the the PCB to down the tube for the fan and everything in between and found nothing like you have pictured above. From that photo, I assume that is supposed to attach to the slot where I have an open space now, that attaches to the fan tube?

I was given some specifications about the sensor and possibly even a part number but have only found it available over the pond from me in Europe. But I think I might have found something stateside that might work. Do you feel the link below might work...
Semitec AP Thermistors | Mouser
The info I received about the thermistor/sensor is as follows
German cost: � 2.79
TS-NTC-103A
Version B value 3976 K
housing epoxy
Tolerance � 0.5%
Connection tinned steel
Basic resistance 10 k
Measuring range -60 - +150 � C
Width 3.8 mm
Height 2.8 mm
Length 17 mm

Do you think the one from Semitec is a close enough match?

And I will be following your diy to test my rear blower fan this weekend when I have a little time in the daytime. Do you feel this can be successfully tested now or do I have to wait until my temp sensor/thermistor issue is resolved?

Thanks again guys, it's so nice to have a community like this, I can only imagine the diagnosis and labor time you are saving me from the local dealership!!!