Fan speed switch only works in the 4th (or highest) position

[kenrosario]

I have an '88 944 Turbo S
When the fan switch is turned to any of the first 3 positions.... nothing. The fan only works in the highest (4th) position. The fuses are fine. Would this be a problem with the relay, the switch itself? Or something else.

Thanks,
Ken

[Lawrence Coppari]

Nice looking car.

Problem could be the resistor pack that is mounted on the blower housing body. It has resistors that cause the blower motor to run at the different speeds. The resistors get hot so there are thermostats on each. If the thermostats get gummed up (like mine did), the blower will only run at top speed where there is no resistor in the circuit and the blower motor gets full voltage.

Try removing the pack and cleaning the thermostats. Mine got gummed up due to an oil leak that was putting oil onto the exhaust piece that crosses over to the turbo. The vapor was picked up by the blower and got onto the thermostats that are in the air stream fouling them. Fouled thermostats prevent juice from getting to the resistors. This can be determined by using an ohm meter once you remove the pack.

[kenrosario]

Thanks Lawrence.
Great advice! I'll check it out and get back to you on how it worked.

[kenrosario]

Hey Lawrence,
That did the trick. Mine were all gummed up too. After a quick clean up, they're as good as new.
Thanks again.

[Lawrence Coppari]

You are most welcome.

[nize]

hey ken, what muffler/exhaust is on your car ?

[kenrosario]

Hey,
It's the Fabspeed cat bypass pipe with their 4" rear section.
Check it out at Fabspeed.com
It bolts in easily but it may be a little loud for most, but I feel it really fits the car's personality. Should work well with your nice 951's!

[kenrosario]

They have a nice 3" rear if you are looking for something a little quieter. Very solid build construction.

[nize]

do you know what the inside of the muffler looks like? does it have baffles or filling?

their 3" downpipe looks like it steps down to 2.5" at the connection so it's not true 3" like sfr's.

[kenrosario]

It's a straight through perforated core with no filling.


You're right about the downpipe. Fabspeed shows a tennis ball test that passes through the entire length of the exhaust but as you may know, a tennis ball diameter is only about 2 3/4". You would be better off with the SFR testpipe. SFR also makes a very nice 3" downpipe that fits on the back of the turbo to make a true 3" all the way through. My buddy has this setup and he loves it. You can even "tune" the sound using different resonators on the test pipe or different mufflers in the rear exhaust.