993 Alan

Hello all,

I searched for this topic and came up with nothing.

Upon starting my cold 993 I stepped out of the car and noticed that the auxiliary blower/cooling fan was on. It stayed on for a few minutes and I got in the car and drove home. Once home (and the engine is obviously warm) I stepped out of the car while it was running.....the fan was off.

So.....why would the fan come on when the engine is cold and be off when it was warm? In fact.....why would it come on at all if the engine isn't overheating? Isn't this fan ONLY for emergency cooling?

Thanks ahead of time for straightening me out.

A

cowtown

You're probably hearing the emissions air pump. On cold starts, it injects air into the exhaust stream to reduce emissions. It doesn't pump on warm starts.

993 Alan

It's definitely the electric cooling fan that sits just to the left of the motor....I can put my hand over the intake screen and feel the suction.

This isn't the fan you're speaking of right?

A

Robin 993DX

Check the connection to the retangular resistor temperature sensor that's on the plastic tube, or it is possible that the sensor itself have gone bad.

Dan V

My blower fan comes on right away if the temp setting on the climate control isn't turned all the way to the blue dot -- why?? -- someone in Zuffenhausen has a strange sense of humor. The same blower that pushes warm air thru the cabin vents also is used for additional engine cooling.

Robin 993DX

Yes, Dan is correct. The electric fan is there it push more hot air to the cabin of the car. If the car is parked and the resistor temp sensor reaches a preset temperature the fan will turn on and the flap door directs air to the cylinder heads and blows the hot air through the vents under the car. That's what those two vents under the engine with the rubber flaps on there are for.

993 Alan

That must be it. Those pesky Germans!

I'll verify it later by starting with the temp. set to cold.

Thanks,
A

Easy_Targa

I am in England and joined Rennlist because I knew you guys would have the answer to this one. I was really worried about this apparent emergency cooling fan operating on a stone cold engine but it seems that "..they all do that Sir. " By the way I burnt myself on that ballast resistor, be careful if trying to test it. It is easy to remove but it could set fire to things.

TheOtherEric

I'm not sure I'd say "they all do that." My blower doesn't normally come on when I turn the ignition halfway when the engine is cold. However, if you disconnect the second sensor that's on the blower tube (above the coil resistor) then it DOES come on if the engine is cold.

Deadeye

With a hot engine my blower fan will only come on if the key is in the ON position (next to start) Isn't it supposed to be on even with the key removed to help cool down the engine? Would the engine have to be very hot for this fan to engage with no key, if so, what engine temp would cause this fan t run?

96 C2
Dennis

Barney1

I just noticed that I hear the flap door opening but the fan not running like it use to when the engine is hot and the car is parked. Where is the fuse or relay for the fan???

Denise993

Sorry for the hijack... Mike R... OMG I LOVE the purple! That rocks! What color is your interior?

Barney1

Classic Gray with painted Sport back seats..

Barney1

Ok I put 12v to the fan motor and it works.. I took out the resistor, how can you tell if its bad? I put a meter across the two terminals and I get no conductivity.The spring looking thing is ok looking but there is some sort of contact that looks shady..

Barney1

Bump