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Shadetree930 Shadetree930 is offline
Wayah Road Warrior
Shadetree930's Avatar
Join Date: Jun 2002
Location: Greenville, SC
Posts: 1,556
It Is Alive!

So I finally have my autoheat and footwell blowers working.

I ordered the micro-switches from (Thanks for the info Scott & Mark) and dove into this yet again.

Here are my findings.

There are two micro-switches mounted on the side of the autoheat control mechanism.

The inboard switch acts as a limit switch. It stops the servo motor when the contact is fully depressed. Wired as shown ...

The outboard switch completes the footwell blower circuit when the contact is fully depressed. Wired as shown ...

I tested each OE switch with a multimeter. The inboard switch was good. The outboard switch failed to complete a circuit in the fully depressed mode.

Ah Ha!

I replaced the outboard microswitch and retested ... Whirrrrrrrrrrrr ... the footwell blowers sprang to life!

I buttoned up everything and sat in the driver's seat to admire my handiwork.

When I reached down and turned the rotary knob to hear the satisfying siren's song of my blowers ..... I got ... silence.

Hmmm. Not what I was expecting. So I tore everything apart to see what I may have missed.

Long story short, the electrical work was done correctly. However for some reason unknown to me, the servo 'fulcrum' was not depressing the new microswitch contact fully enough to clomplete the circuit.

I did some McGuyvering to the fulcrum to fix the problem. I used a screwdriver to expand the gap in the fulcrum by maybe 2mm (at the point indicated in the pic below), moving it closer to the microswitch contact.

Autoheat problem is now solved.

Thank you all for your contributions.
02 996tt White
87 930 GP White (Sold)
87 911 Targa Guards Red(Sold)

Last edited by Shadetree930; 11-19-2010 at 07:01 PM..
Old 11-14-2010, 11:24 AM
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