Air cooled with no air

[coldstart]

Poor subject heading but it is Monday morning. My P-car has no air flow into the the cabin-- no heat or fresh air from the vents. When I first got the car last year both the heat and the air controls worked poorly. My car has optional A/C which is not functional.

Three questions:

1. Is the Behr fan in the hood trunk responsible for air flow through the cabin or is there another fresh air blower?

2. How do I fix this and what parts do I need?

Thankfully it is a targa so air flow is not as important as in a coupe. TIA for the help.

[tonythetarga]

Porsche has a different blower for every function. The fresh air blower for defrost is located in the trunk behind the cardboard panel up against the firewall. There is a fan in the engine compartment for heat that should come on when you lift the heater levers between the seats. Additionally there are footwell blowers with a 3 speed fan switch on the console. The air conditioning system has another blower in the smugglers box in the trunk under the carpet behind the gas tank. And there should be another fan for the front air condenser in the trunk as well up by the battery.
There are fuses and/or relays for each system, some in the trunk and some in the engine bay. you probably want to check each system individually and then decide what you want to fix first.

[javadog]

You've got more than one problem, if you get no fresh air or heated air, as the systems have seperate intakes. The fan in the trunk supplies fresh air. Ducts at the sides of the engine cooling fan supply air for the heating system.

This subject has been covered many times; try doing a search to get pictures. Also, read your owner's manual to get an idea of how to operate the system. Nobody can tell you what parts you will need, if any, until you do a little diagnostic work into what is causing the problem.

For heated air: Air is blown through ducts at either side of the engine cooling fan into hoses that attach to the rear of the heat exchangers. The heated air is then routed through a hose from the front of the heat exchanger to a flapper valve that either directs air into the car or exhausts it under the car, depending on the position of the levers between the seats. If directed into the car, it passes through a silencer inside each side of the car and then passes into a hose forward of the doors and up into the trunk. It is routed through a distibution box on either side of the trunk that sends the air to the dash vents or vents in the footwells, depending on the position of the lower lever on the dash.

For fresh air: Air is input into the blower fan housing through the intake at the top of the trunk lid, if the upper lever on the dash is moved to the right. The air is output to the same distirbution boxes in the trunk as used for the heater. The middle lever on the dash controls where the fresh air is directed, in the same manner as the heated air.

Study each part of the system on your car a few minutes and it's quite easy to figure out. Troubleshooting is pretty easy. Make sure all of the components and hoses are installed correctly and check for proper function of each component when you move the levers. Start at the air intakes and work towards the cabin, one component at a time. Adjustment is easy as well, once you figure out how it all works.

You can always buy a shop manual for the car. Most of them have a desription of the system and the adjustments needed.

JR

[javadog]

Assuming you were talking about your '72 Targa in your post, you can quit looking for the fan in the engine compartment, the footwell blowers and the three speed switch on the console that Tony mentioned. They were used on the later cars, not the early ones.

JR