a/c freeze protection switch

[mytrplseven]

Could anyone please send me a picture and location of the a/c freeze protection switch?
I've seen so many articles that circle around this thing but no pics and location. Supposedly it's on the cowl.

[9FF]

Here it is on the intake side of the blower so that if the temperature is bellow 5 degrees it will not allow the air conditioning to cut in as it may cause the evaporator to ice up.

[mytrplseven]

Thanks for your answer. Maybe now I can sort this out. Funny that I can't find a replacement part on any of the providers for this. I was hoping it wasn't down in the evaporator. I hate getting under there at my age.

[9FF]

Originally Posted by mytrplseven

...Funny that I can't find a replacement part on any of the providers for this....

The part number is stamped on sensors on all Porsche’s but I’m pretty sure that sensor has been nla from Porsche for some time now. If you’re lucky there may be a manufacturers name also stamped on it and an OEM part number so you can track one down that way.

[mytrplseven]

I just pulled the item you suggested and it's actually the outside temp sensor with Green and Yellow wires. The freeze protection switch has white with black and black with white wires. So, I may end up under the dash after all if I can't get to it from under the hood. I'll keep exploring. Thanks for your efforts.

[9FF]

Originally Posted by mytrplseven

I just pulled the item you suggested and it's actually the outside temp sensor with Green and Yellow wires. The freeze protection switch has white with black and black with white wires. So, I may end up under the dash after all if I can't get to it from under the hood. I'll keep exploring. Thanks for your efforts.

Mmm ok, are you sure about that?

I know it senses the outside air temperature but it’s only fitted to cars with AC and the thermistor on it operates at only one temperature to prevent the AC from operating at very cold temps. The only other sensor I know of is on the side of the climate control unit which is set to sense a minimum interior temperature of 18 degrees, but that’s obviously not freezing.

[mytrplseven]

Yes, I'm very sure. I pulled back the cover on the connector to expose the wires and the colors were appropriate to the wiring diagram. I don't know the values of certain components but this sensor is in perfect position to sample the outside air coming into the system. Since the ice protection designation includes the word, "evaporator", I'm getting the feeling that it is inside the HVAC unit near the evaporator.

On another note, the wiring diagram shows the ice protection wiring going through a 6 pin connector as do the wires from the outside temp sensor. Do you happen to know the location of this connector?

[mytrplseven]

picture of the 6 pin connector:

[9FF]

Originally Posted by mytrplseven

Yes, I'm very sure. I pulled back the cover on the connector to expose the wires and the colors were appropriate to the wiring diagram. I don't know the values of certain components but this sensor is in perfect position to sample the outside air coming into the system. Since the ice protection designation includes the word, "evaporator", I'm getting the feeling that it is inside the HVAC unit near the evaporator.

On another note, the wiring diagram shows the ice protection wiring going through a 6 pin connector as do the wires from the outside temp sensor. Do you happen to know the location of this connector?

Ok, I think there is some confusion in the terms used. What is referred to as the outside air sensor is correct, it measures outside air before it hits the blower. But it’s sole purpose is tell the AC control unit that the outside temperature is below 5 degrees (freezing) and then the control unit will prevent the AC from being turned on in order to save the evaporator from freezing as I mentioned above.

The other “freeze” sensor is like I said on the side of the climate unit assembly itself. It’s sole purpose is to sense ice forming on the evaporator and send a signal to the AC relay to turn the AC off.

Sorry I don’t know where the 6-pin connector is but I’ll guess it’s near the climate unit under the dash. However like I mentioned earlier the location of the freeze/ice sensor is on the side of the climate unit. Here is a picture of it from the workshop manuals.

Again, working on these cars without a manual means you are constantly asking folk here to look things up for you, gets old fast but happy to help. You just have to hope someone has the time to look stuff up in the manuals for you and you’ll have to wait a while for an answer. My previous offer to send you all the manual PDFs still stands but I haven't heard back from you so I guess you must prefer to post all your questions.

[mytrplseven]

Ok, that is on the HVAC unit under the Dash behind the climate control. In either case, it looks like I'm going to have to get under the instrument panel again. I bought another climate control from a vendor and it, unlike the one I replaced, has plug in switches vs the soldered in ones on my control head. The circuitry inside looks totally different as well but I'm hopeful they are essentially compatible.

[mytrplseven]

Here's a graphic from Clark's Garage that shows it really well.

[9FF]

Originally Posted by mytrplseven

Ok, that is on the HVAC unit under the Dash behind the climate control....

Yes, terminology again lol. What you call the HVAC unit I call the climate control assembly as it does both heat and cold, and I call the control panel the climate control panel.

That Clark’s photo is straight from the factory manual, glad you eventually found it.

[mytrplseven]

Where in Florida are you? I'm in Groveland, just off hwy 27 North of Clermont.

[9FF]

Originally Posted by mytrplseven

Where in Florida are you? I'm in Groveland, just off hwy 27 North of Clermont.

I’m in Stuart SoFl about midway between Orlando and Miami.