Auto Heater Problem

[kbruz]

A few weeks ago my heater stopped working on my 86. I read lots of information on prior posts and found that the plastic ball socket was not attached to lever arm. I'm off to buy that part tomorrow. Except I had lots of problems pulling the arm free as it was trapped under the lever arm. FInally pulled the passenger seat so that I could get my hands in there.

THe one thing that I did notice is that without the connecting rod attached, the heat blower in the car does not work. Is the switch that operates the blower inside the cabin attached/controlled by the heater servo motor? Or do I have a secondary problem?

[kbruz]

bump

[imcarthur]

kbruz

You have discovered one of the biggest mysteries of a 911.

The rod attaches to a lever that opens & closes the flappers on the heat exchangers to start warm air flow. When you turn the dial between the seats, your rear blower should come on. If not, you start to search . . .

The first step is to determine what part of the system is working & which part isn't. Do some searches on Autoheat or blower etc. Many of us have problems.

See thread to get you started. Check the thread links in the post 1/2 way down the page.

Good luck.

Ian

[kbruz]

I think that I found the problem with the heater. The issue is well posted on this website, but I thought that I would poste some pictures regarding the problem. The linkage between the servo-motor and the heater lever broke. Here is a picture of the old part and the new part.

The new part is PN 999-168-021-40

[kqw]

Just for reference....on the '86 model...

The rear engine compartment blower will activate upon pulling either the right or left lever. You do not need to activate the switch between the seats.

The switch between the seats will activate the footwell blowers but only if one or both of the levers are pulled.

[imcarthur]

kb

Re the pic in your other thread, the distance between the two ends of the rod should be 118mm +/- 2mm. (4.646") center to center.

kqw

With Autoheat, there are no levers between the seat. Just the control module with a rotary switch. The main rear blower comes on with any selection.

Ian

[kqw]

Thanks Ian, I thought "auto Heat" began in '87..

I could be wrong though.....

[imcarthur]

kqw

No, Porsche had it as an option at least as early as 84. Thread

I collect autoheat threads. A footwell blower problem that I think I have figured out - not solved - just figured out. I was thinking about amassing all the info into a troubleshooting faq.

Ian

[kqw]

Thanks Ian,

My apologies for assuming...