backitoff

Sorry that this is such a common subject, but I have searched lots but cannot find anything that is the same as my heater problem.

Neither of my front blowers work. I have recently bought the car and they have never worked in my ownership.
The symptoms are as follows.

Initially I figured it was most likely to be the rear blower and it also takes up so much space, so I carried out the Carrera Cup rear blower delete as per bubbalouie's excellent post. https://rennlist.com/forums/8964599-post79.html

The only difference I made was to run a switched live from the coil to pin 87 instead of his relay.

I thought this would sort my problem but it hasn't.
I have accessed the front bulkhead and only 3 of the 5 servo's seem to do anything when the CCU controls are moved.
The bottom slider does nothing, Fan **** does nothing. Demist button will not stay on unless the button is held in.
Any advice to piont me in the right direction is appreciated.
Thanks

ras62

ToreB's website covers the systems in great detail. Could be the fan amplifiers are not working at a guess, but it would be a good idea to put the hammer diagnosis tool on the car to test CCU / servos etc.

http://www.porschehvac.bergvill.com/

JasonAndreas

Do the front fans spin when turned on with the temperature set to the blue dot?

backitoff

Hi Ras62, yes I have looked at ToreB's web site and not being 'electrically enlclined' I'm struggling. I have bought his diagnostic tool and plug adaptor and awaiting its delivery.

Hi Jason Andreas. Front fans do not spin.............period!

964George

Don't mean to state the obvious but have you checked the fuses...

schwarz930

I've just been through this. Both my front fans had seized as had four of the five servos. I removed all the servos and both fans and managed to free them all off. I still have a couple of gremlins but mostly it all works now.

964TOK

Nice one Jon.

I had the same problem with a couple of my Servos. I got them going but they gave up a few weeks later. I ended up getting some 2nd hand ones from Porsche apart. However, these went back and forth as they did not work either until I finally got a pair that worked and have been in the car for over 2 years now. The fans are crazy money new, so good u got them going.

backitoff

Thanks George, fuses all Ok Not sure on Seizing, I guess I need to completely strip the front units down and find out. Unless anyone has any other suggestions?

ras62

you can partially strip the covers and check if the fans move or are seized. These fans are controlled by solid state amplifiers that do go wrong. They appear on ebay quite often.
It could also be a CCU problem. Was the rear blower working before the bypass was installed, if not the fault could be relay related? Easiest to check with the systems with Bosche hammer tbh.

www.964uk.com/Documents/964%20Heating.pdf‎