Repair of auto heat control

[Rick Cabell]

Does anyone know who repairs the auto heat control that sits between the front seats.
The unit with a dial that started a round mid 70’s.

[mysocal911]

Originally Posted by Rick Cabell

Does anyone know who repairs the auto heat control that sits between the front seats.
The unit with a dial that started a round mid 70’s.

Found this, check here; https://www.systemsc.com/Parts.htm

[cpa]

Contact Kris Rose, mailto:JamesDean59@gmail.com
He is a forum member, quality electronics repair, reasonable price.

[stevie 77 930]

I shipped mine to Tore Bergvill in Norway

https://www.bergvillfx.com/products/911-autoheat

[Flat6pac]

Did you change the nylon connectors under-the right side access plate?
Need to remove the seat to access the rod and connectors
Suggest you replace the flapper heat box cable covers as they fill with grime and make the automation work too hard.
Bruce

[Rick Cabell]

Thanks guys. The unit seems to be dead, and it is getting power.

[wazzz]

What car? I mean what model year?
There are basically two versions of the electronic card (PCB) inside. Both work the same way but use different components. Send the unit to systemsc, they know how to deal with it.

[Rick Cabell]

77 3.0 Carrera

[wazzz]

OK so it must be the earlier generation with BD175 (or 131 or 235) / BD176 (or 132) transistors in a H bridge. One of them can pop when the mechanism is binding or a limit switch does not open when it should.

[mysocal911]

Originally Posted by stevie 77 930

I shipped mine to Tore Bergvill in Norway

https://www.bergvillfx.com/products/911-autoheat

Why a ship to a faraway location, when a local source is here in SoCal; www.systemsc.com ?

[mysocal911]

Originally Posted by Rick Cabell

Thanks guys. The unit seems to be dead, and it is getting power.

There are many problems that occur with unit besides "power";
1. disconnected temp sensors - 3
2. damaged micro-switches
3. stuck motor armature
4. failed motor control board
5. stuck heater flaps
6. damaged potentiometer, and or knob setting

[rokemester]

There are some excellent threads on this topic. I swapped my box for a used unit, replaced sensors based on found intelligence here.

[Rick Cabell]

Sent to LORAN, thanks for all the good info.

[blucille]

Originally Posted by Rick Cabell

Sent to LORAN, thanks for all the good info.

you mean "Dave" ??

[Rick Cabell]

Systems Consulting