AC fan only runs on high speed
 

My 1983-911SC with AC,the fan only works in the high speed setting but not on the lower settings,do I have a faulty resistor pack?I replaced one of these on my sons VW Jetta and it fixed it.If this is the problem,where is it located on the SC?Any advice is appreciated.Thanks

On a Carrera the resistors are located behind the passenger kick board, so I would look there first. Also on a Carrera, the 2 lower speeds are controlled by resistors while the high speed is not. It makes sense that your resistors are damaged.

Thanks for the reply,after looking at other posts regarding AC issues,is the fan in the passenger side under the floor board?I am thinking the resistor pack is in the fan housing?Can the resistors be purchased seperately?What are the resistor values?I am guessing it is cheaper to buy the resistors from a vendor than it is to buy the pack from Porsche?Sorry for all the questions but I am new to 911 AC system and do not fully understand it yet.Thanks

The fan is part of the evaporator assembly, which is in the 'smuggler's box' - look for a panel in the floor of the trunk aft of the fuel tank, passenger's side.

The resistor pack is mounted on the passenger footwell firewall. Remove the carpet, and you will find a wooden panel. Remove the three screws and remove the panel. The resistor pack will be exposed.

First thing you should do is buy a copy of the Bentley manual for your car. It really helps identuly components, troubleshoot systems. etc. Its a valuable resource. Buy it right here at Pelican.

Sounds like your resistor pack and/or associated wiring is toast. Best bet to replace the pack is one of the many Porsche dismantlers. Very spendy from the dealership.

had the same problem with my 87, the resistor pack on the passinger side was disconnected, just pluged it in and all was fine. The AC still sucks though.

What if my A/C fan quit working altogether? Before I start going through all the usual troubleshooting techniques is there anything that jumps out at anyone? It worked when I bought the car but quit working one day all of a sudden.

OK, I'll play......

The fuses have a nasty habit of developing a layer of oxidization on their end caps, which causes them to go open circuit. The fix is simple - find the fuse, remove it, clean the ends with light scotchbrite, replace the fuse [along with some silicone grease to prevent this from happening again].

I've had several fuses quit this way - simply twisting the suspect fuse in its holder can sometimes work if you are stranded.