gasongasoff

I think you're right! I disconnected the fan sensor to see how long it would take for the error to pop up, and the error appeared while the car was moving.

Now the next thing I need to do is figure out how to get the fan to run at high speed (I believe there are 2 speeds) whenever the car is traveling below highway speeds.

jhbrennan

I think the dual speed fans are in the front by the radiators.

floatingkiwi

Where's the fan sensor?

gasongasoff

It's on the left side of the engine, adjacent to the manifold. There's a wiring harness sticking out of it, and it plugs into a rubber socket.

StormRune

Yep, I think Mr. Brennan is correct, I've only heard the deck lid fan run at one speed and the electrical connector only looks like a single speed hookup. And by the way, the front fans are continuously variable.

gasongasoff

Strange. Mine seems to have 2 speeds. One is very loud and the other you can't hear unless your ear is up against the deck lid. The wiring diagram also seems to reference 2 relays, one for each speed. I guess I'll have to play around.

Macster

if it was better Porsche would have the fan spinning the other way.

The lid should remain closed if the engine is hot enough the fan may come on.

The idea is the fan blows the hot air down and out from under the car. This avoids pulling the hot air up from the exhaust and "cooking" the items in the engine compartment.

My Turbo has an extra fuse when it is installed the engine compartment fan runs all the time the engine is on (and still comes on when the engine compartment temp gets too high). The battery is unaffected as is the fan by this extra run time. And the fan gets a workout after the engine is shut off. It is *hot* here today. 93F when I went lunch and even after just a few minutes in picking up some food to go when I came back to the car the engine compartment fan was running.

I'd rather replace the battery more often even the fan compared to the cost of dropping the engine to replace the injectors or engine wiring harness.

user 72902

Is that from the factory or did you add that fuse to get the fan to run whenever the ignition is on?

gpjli2

I have experienced that. There is another scenario. In high ambient heat after hard running my engine bay fan will sometimes go on after I park and shut motor off. This I assume is to eliminate heat soak in the motor. Best to let car idle a bit when engine temp is up and outside temps are high.

StormRune

Here is the wiring diagram for the deck lid. There is only one connection pair to the fan. Typically a two-speed fan would have a winding in the motor with a central tap and would require 3 wires, 1 ground, 1 to the low speed tap on the winding, and 1 at the end of the winding for high speed. I don't see three wires here. I doubt there is a low speed, you must be hearing something else or the fan blades just spinning due to air flowing past it as it convects.

gasongasoff

Interesting! I do only see 1 relay on your diagram. Here's the one I have from alldatadiy. My fan also only has 2 electrical terminals, but there's no reason why you couldn't simply supply a lower voltage for a lower rpm (i.e. 12V for high speed and say 7V for low speed).

gasongasoff

Hey! Which fuse? How did you do this? Thanks.

StormRune

It appears you have taught me something here! I see on your diagram that a line labeled "Resistor Line" becomes part of the active circuit when the relays move into the low speed configuration... so you must have that right. I didn't expect them to do it that way. The only behavior I've ever noted seemed to be binary.

KNS

Does the fan come on whether the lid is up or down - after the motor is shut off?

On the 993 the engine blower fan is temperature dependent (though the cooling operation is slightly different). The fan will come on whether the lid is up or down.

jhbrennan

Fan will not run if lid is open...fan will run with motor off and lid closed.