SNOWBIRD

Just had to put the top up this weekend... Was pretty chilly out. My question is: Am I supposed to have heat when the car isn't going 70mph? Doesn't seem to give me anything but cold cold air at any speed under that, do I have a problem?

Andy Roe

Yes, you should have heat!! Check the rear blower fuse in the rear fuse box. It should be a 30A fuse (not 25A as it was changed by Porsche). If blown, it's a sign of your rear blower on its last legs!! The bearings have a habit of seazing. Replace the fuse first & see how long it lasts. If it blows again quickly, you need a new blower! It's now a 993 part.

Andy

SNOWBIRD

Thanks Andy... Just looked, fuse good.. I get air, it's just cold air.

DarrylH

Can you hear the rear blower fan running? At any temp setting above ambient you should hear it in the engine compartment. If it's running, then likely your servo controlling air mixing is stuck in the cold position.

jenskleis

Hi Snowbird,

As Darryl says, it sounds as if the servo controlling your hot/cold air is stuck. On John Miles' 964 website there is an excellent guide to cleaning your servos.

http://www.porsche964.co.uk/technical/servos.htm

Good luck!

Andy Roe

You should also check to see if the rear blower is plugged in. I've heard of mechanics forgetting to connect the power back in after a service!

Mark Brook

Andy,
30 amp, are you sure ? I've got a 25 amp in mine....maybe thats why mine keeps blowing ?

Mark.
90C2

Andy Roe

Mark,

I think it was originally a 25amp, but later changed to a 30amp. On my old '90 C4, the label on the box said 25amp, but a 30amp was in place. On my '91 C2, the label says 30amp! I have a feeling it should have been changed by the dealer during the cars early service years.

Andy

Mark Brook

Andy,

Do you think there was any changes in the wiring between early and late cars then? What problems could I be letting myself in for if I change over to a 30 amp? I remember reading the horror stories of balast resistors catching fire etc....I checked mine at the weekend, and it was the new model (002), but was very charred and needed a good clean-up. Maybe I should treat myself to a new one! Sorry to thread-hijack.....

Mark 90C2

SNOWBIRD

I need to ask my co-pilot if she was getting heat on her side (I doubt it)... Anyones guess why would all the problems seem to go away at speed?
Thanks for the lead to Johns site... looks easy... But you're talking to a guy who couldn't fingure how to get the alternator belt off last weekend, and still can't find where to add windshield washer juice!

Jeff Curtis

FORGET the 25/30amp issue, BOTH fuses will work, wiring is NO different from early to late cars in regards to the heater blower assembly.

You problem is a mixer servo...I still have yet to spend 5 minutes to identify which one is stuck on my 964...in the HEAT position!

This made for an uncomfortable track weekend...until we took the heater hoses off the heat exchangers.

jimq

look inside the gas fill flap. Its the other hole with the plug in it !

SNOWBIRD

Just went down to see if you were spoofin me! New Jersey is one of the two states that does not allow you to fuel your car yourself.... I never woulda found it! LOL! I asked a bud of mine who has a '94 3.6 turbo (since new) where it was, he had no idea, said he never used the wipers or washers! I hope you guys at least find my really stupid questions entertaining at least. I have to say this is the 1st car I have ever needed to use the owners manual for and IMHO it leaves a lot to be desired.

jimq

We are a serious group here . Would we ever kid you