x50type

My ac will now run for about 30 seconds then the the No 1 25 Amp fuse [blower motor] in the front fuse box keeps blowing and so stops the ac compressor.

All relays seem fine.

What should I check next?

IXLR8

Find out what is drawing so much current.

x50type

Find out what is drawing so much current.

Ay, there's the rub - perchance to find, to locate, to repair..............................

To start wither?

x50type

Checked the blower motor - its fine and the blower motor fuse does not blow.

however, the fuse does blow when i put the a/c on.

anyone else had this problem?

IXLR8

Which blower motor?

Fuse 1 appears to be feeding both the left and right blower motors in the luggage compartment. Did you physically check to see if each spins by hand without any drag? You'll have to remove the cabin air filters to do so.

It also feeds the Control Unit / Control Air Conditioning, Heater.

993/907

Try running the ventilation fan wide open (4 notches?) without the AC on.

If it pops the 25a fuse just on ventilation, the big blower in the back might be creating the over-amp draw.

Gordo

x50type

IXLR8 & 993/907

Grateful for your view of the problem - appears the passenger side blower fan is not turning very freely, it certainly wont spin round like the driver's side.

here is a photo of the fan. i don't see any shaft lub point.

Is it possible to pull off the fan from the motor shaft?

Thanks

x50type

Passenger side blower.

IXLR8

"Not turning freely" as in there is a noticeable difference?

Do you have a DMM with a 10A DC setting? If so, measure your current draw of the driver's side fan and compare it to the passenger's side fan. Start with the lowest blower fan setting and work your way up.

Yes. There is a fan motor puller shown in the Porsche Repair Manual; pages 1039-1041.

If you can get the fan motor out by itself, check to see if the bearings are ball or sleeve.

I'd do a current test first before pulling anything apart. Note, that blower fan is $$$.

ToreB

These links may help:
https://rennlist.com/forums/964-foru...ront-dash.html
http://p-car.com/diy/ac/

You have to pull the complete air box out to get to the fans. A lot of work they say. Be sure to test them at all speeds when putting them in, the fan vanes must be completely centered to avoid vibration at high speed.
Cheers,
Tore

x50type

IXLR8

Yes there is a noticeable difference between the two blowers. Appears the passenger side one has bearing problems [sintered bearings dried out after 15+ years in service?]

ToreB

Great links - thanks so much.

Its is not quite clear if the gas tank has to be taken out to get to the air box housing and then the blower motors, or if it can be done just by removing the fuse box and fire wall and pollen filter.

And for more bad news - my local Porsche dealer tells me the price of a new motor is $965................
The cost of left and right motors is the same - $965 each and they are not interchangeable.

[I see they can be interchanged by modifying the air box housing].

IXLR8

I'm sure they are worth every penny.

I am amazed that they come up with such BS pricing when a blower motor is a blower motor when it comes to production. If mine ever goes, I'll do my best to try to replace the bearings...after all, why replace the rest of it if there is nothing wrong with it...sort of like plug wires.

kb

Is this problem fixed now? Have same issue since yesterday. Trying to troubleshoot myself.

Linnm

check price at AutohausAZ. (I recently replaced my evaporator--Porsche price around $1200, Autohaus was $394 (made by Behr, the OEM)

kb

Do you have a part number for the blower motor resistor pack?