Heater blower stopping
 

When I put my blower on with the heat, it works for a minute or so and then stops. However, it works fine at all speeds with the AC on. Seems like it cuts off over 18 degrees C. Is there a temp sensor that shuts the blower down as a precaution for some reason. Doesn't make sense for the blower to work fine with cold air but not with heat. Problem just started. Any suggestions would be appreciated. Thanks

I was having a similar problem. Blower worked fine if the temp was set to the blue dot. Only Blew for a few seconds if the temp was turned up from there. I also noted that if the windscreen defrost button was pressed in it blew for the same amount of time (about 3 sec) and then shut down.

My problem was related to the 1st stage blower in the engine compartment. If it is not functioning correctly you may see this problem. The difference here is that your saying it blows for a few minutes so it may not be the same problem.

Check the Rear Heater Blower fuse that's in the engine compartment. If this blows, the heater will not work. The most common reason for it to go is because the bearings on the rear blower motor have gone bad, but try replacing it and then if it goes again check the blower itself.

Thanks guys, It may be my rear blower, it did sound like the bearings were going based on recent noise. I took it apart long time ago and lubricated it and it seemed fine. I know it is running on borrowed time but it still runs. Thanks for the leads, good place to start.

Literally just solved this exact problem....

Here is a link to the thread I started... Should solve all your problems, and will cost effective solutions.

Best of luck

https://rennlist.com/forums/964-foru...king-help.html

Just an update. I rebuilt my blower with a backup motor I had and installed it and still not working. Checked the fuse and it was blown, replaced it and all blowers works fine now at all temps. So I guess when my original blower was screetching and grinding before I knocked it to realign the vanes, it overloaded without me knowing until I tried to demand heat. Anyway, it was another good learning experinece to fix it. Thanks for the suggestions.

you can swap mine out... it runs all the time :)

I think the Porsche engineer who designed this blower AC/Heater logic system got his walking papers that afternoon and decided to take it out on the design. From all the article I read, there are a slew of different scenarios with this blower. I think I read that if the servos are not operating right , that would cause erratic behavior as well. I worked on those too when I first got the car, that was an easy fix.