Cabin heater fans

[chrism964]

Just a post to get my fears confirmed as I doubt they will be dispelled.

Was taking my son to school this morning when we both noticed it was unpleasantly hot in the cabin of the car.
Adjusted the climate control unit to cold - nothing happens. Twiddle the dials and move the knobs - no change in anything at all. Then I notice there is not a sound from the fans whatsoever. Press the windscreen demist - zero response. Rear blower fan not operating either.

Boll***s. CCU is busted I think. That's not good.

Check all the fuses - rear fuse box 30A - good
Front fuse box - Fuse no1 - 25A blown! - hooray I think problem solved and a 8p fix!

Restart car. Fans are on at position 0,1,2 and 3 but then stop dead. Check fuse again - blown - s**t. Replace it again. Restart CCU on 0,1,2 - fine. Drive for 30 miles no problem. Fans in the cabin working fine. All servos working hot air, cold air, air in the footwells only and air to the screen only......... Right press the demist button - high speed fans and then dead. Check fuse - blown.

I guess this means that one of the front cabin fans' bearings has died and whilst the fan motor is happy to cope at low speed at high speed the current draw, due to the resistance against the motor, is so high that it blows the fuse.

So replacement fans is the cure I think. £500 each or £250 2nd hand and likely to be worn. Don't think it is worth replacing just one and I don't fancy replacing with a 2nd hand fan as it is likely to be FUBAR too.
Having looked at the various threads I really don't fancy the time and effort involved in removing and dismantling the fans/motors to replace the bearings and or the fan motors.

Whilst I love this car. I really really do hate the prices of some of the parts.

Any other thoughts?

 

[Steve Brookes]

When I had a problem with fuse 1 blowing it was caused by the final stage relay failing. Replacing it with a used one from Ebay (£50) sorted it.

 

[chrism964]

Steve, as always, you prove to be extremely helpful.

I will replace the relay (as this is considerably cheaper than the fans)...........

 

[ras62]

If you need a replacement fan take a look on ebay.de and search under porsche 964 Gebläse it shows the motor at £135 A huge saving on what the OPC charge.

http://www.ebay.de/itm/BOSCH-Geblasemotor-Geblase-Luftermotor-einzeln-Porsche-964-993-/120966163554?pt=DE_Autoteile&hash=item1c2a252c62

 

[T911UK]

Just to clarify, that link is for a rear heater fan unit motor, not the front ones. We have that at £115

 

[ras62]

My appologies...I thought we might have a less expensive fix for a moment. That fan looks remarkably similar to the ones in the front, does anyone know the difference?

After some research it would seem the right side fan is shared with a Mercedes 190! The left fan has a slightly different winding shape but with a little work to the housing the right side fan can be used.

http://forums.rennlist.com/rennforums/964-forum/745753-front-right-blower-motor-part-number.html

 

[JCX]

Hey guys, new here. I spent a long evening last week removing and greasing my heater blower fans as they had started to whine in operation. 6 or so hours later and they are silent Time will tell how long the grease lasts but I used a commercial teflon grease product which is reputed to last 8-9 times longer than ordinary grease. Was a heft task so I am hoping I too don't need new fans. they are a crazy price.

Chrism964, did the relay swap out fix your issues?

 

[chrism964]

I have not managed to get around to getting a replacement relay yet.

Currently just limiting the fan speed to 2 and replacing the fuse when the kids won't listen to 'please don't play with the heating controls..............'

I will update when I have done something about it.

 

[RLambert]

I'd try lubricating your fans first, like JCv964 did. It doesn't take that long to do, it's just a bit fiddly !

If they've never been done before then they are likely to be stiff to turn which could be why you are blowing fuses.

 

[JCX]

There are loads of resources on the web to inform and guide your efforts if you do access and remove the fans to lubricate them. I documented bits of my work here and included the major sources i used in the process. Was had work but so far well worth it.

Good luck!