Clint's 944

My fresh air blower stopped working! I checked the fuses, relay and even looked at the resistors. I'm thinking it is the climate control unit but everything else works on it.
Before I shell out the dough to buy another one, how can I test the fan switch to make sure it is the problem? I read in the archives a small reference about pulling the plug and jumping pins.....but didn't say which ones?

Any help...is appreciated!

Bri Bro

Pull the plug and try this for a quick test.

Ground C1 for lowest speed
Ground C5 for highest speed.

Clint's 944

Nothing happened......

this is bad, huh?

Bri Bro

No, it points to another problem other then the fuse. Check fuse 14 and 24 (30A) and then relay G1 (Fresh air relay).

Clint's 944

Checked and replaced for good measure both fuses and relay. Relay clicks as I install it so there is definitely power there as well.

Bri Bro

Check at C5 of the switch plug, should be 12V(ignition on). If no voltage, then I would say the fresh air blower is broke.

Clint's 944

C5 of the same plug I just grounded? The plug on the back of the Climate controller?

I don't think it is the blower because I hooked up another blower from my old S2 and it does the same thing. I then ran a straight wire from the battery to test both blowers and they both ran a full speed.
I did notice that I don't get any power to the two prong power wire to the blower but I am assuming this is varied by the fan switch.

ARGH...I hate electrical issues!

Bri Bro

Well, that is good news, it looks like wiring. The power should be on one side of the blower all the time, the switch supplies the ground path. So, track down why you are not seeing power going to the blower. The other lead to the blower should have be straight to ground with the blower switch on high speed,or speed 4. As the blower switch is changed, more resistance is added (about 0.25ohm) for each lower speed. All resistance checks should be done with the G1 relay pulled since it grounds the power lead to the blower when it is not turned on.

So, check the wiring between the blower (pin 2) and Fresh air blower relay G1, pin 30. Power goes to relay G1 on pin 87 which is connected to fuse 14.

Clint's 944

OK, so I finally got a chance to go mess around with it again and I know what's wrong....

The relay does not seem to make contact when fully seated! If I put the relay in just a tiny bit, everything works...if I push it all the way down...the fan stops.

kingston944

HUH the same thing happened to me with the DME. If I pushed the DME in all the way then it would not run. I ended up putting in a used fuse box and everything works excellent now.