rollis

Yep, the clip is intact. The fans blows but even when it's dialed to "O" it blows a little air thru. I'm hoping a fellow rennlister's could give me a punch list of what you would check. I bought a multi-meter today but I need to learn how to use it properly. I pulled the trim off to look at the cabin temp sensor and there is nothing connected behind the trim, looks like some tubing should be attached there...a pic would help alot. It's getting cold and I need some help !
87' 944S

major

There is a rubber hose connection that belongs behind there. May have nothing to do with your problem though.

rollis

Where is the actual sensor located. I need to fish the hose out and attach it anyways.

Dal Heger

The fan is supposed to blow, even when on the 0 position.
Check the simple things first.
Make sure that you can see the actuator motor under the dash, driver's side, toward the center console under a black plastic cover, move when you turn the temperature **** from hot to cold. This actuator controls a flap inside the mixing box and allows heated air to come through as needed.
I doubt that you have a problem with the air temp sensor. Look elsewhere.

By default, the heating system is designed to fail on full hot. To make sure you don't freeze.

I have had to replace one of my electronic actuators because water got into it somehow (still don't know how) and rusted the electric motor solid.

Good luck. Check the simple stuff, it's most likely not electrical.

Dal.

Dal Heger

if you're talking about the cabin temp sensor, it's attached to a small rubber hose that draws air from the dash, right next to the clock. The actual sensor (and tiny fan) are way at the back of the dash, behind and above the glove box. Don't worry about it, it'll read just fine, even when it's not drawing air from that little hole - it's still reading cabin air temperature.

Dal.

rollis

Thanks Dal Heger....that's a starting point. Does the car have to be running or can I troubleshoot using the accessory on the ignition switch. Sorry for such newbie questions, it's that I've never had to repair something like this.

Dal Heger

As long as the ignition is on you should see the actuators move. The car does not have to be running.

Dal.

chitown928s4

I just fixed mine where only the vents worked. Look under the hood and under the plastic where the blower is and check to make sure the vacuum lines are connected. Even if they are remove and replace could be a stuck door.

Dal Heger

The lines and actuators under the hood are only for the fresh air intake, versus recirculated air.

All of the actual controls for the vents/temperature mixing are electric actuators under the dash. There are three of these.

Dal.

944CS

check the fuse

rollis

All the fuses are good, forgot to mention that. Are the actuators under the same area as the heater clip. I have'nt been able to check them yet...got a nasty cold. Should I see the rods moving?

Dal Heger

Yes, the actuators are what move the clips.

rollis

The actuators are not working while I dial hot to cold. I also found a hole in a vacuum hose, I'm gonna replace it regardless but what will it affect as far as the heat goes? Trying to post pics....gimme a minute

rollis

Are these the actuators ? Pic of the hole in the vacuum hose.

Dal Heger

Yup, those are the actuators. Don't worry at all about the ones under the hood, they are just for fresh air/recirculation, they obviously run off the car vacuum. Replace the rubber elbow to get rid of the leak, but otherwise don't waste your time on them, they do nothing as far as heat is concerned. Clean out the leaves while you're under there too. If you want to, you can also get a pack of "heat register filters" from your hardware store and attach them to the air intake grates. I used four zip ties to attach them. They'll keep the dust and leaves out of your car.

The electrical ones - you can check the operation by doing what you're doing, turning the **** from hot to cold, and by moving the vent sliders. The bottom one (left on the picture) is one of the vent controls, there is another one on the other side of the console, passenger footwell. The one on the right should be the one for the temperature control if I remember correctly.

You can also pull the plug and test it with some jumper leads to see if it works. You'll have to check the pin configuration. Should be in the factory manuals.

Dal.