BigAl1

Can anybody post up the rest of this schematic? Want to see the lower part of this - where wires 1, 2 from the lower part of the setting motor go to. Also where wires 12, 9, 2, 1 from the control head go to.
And, what type of signal does the setting motor need to move?

Alan

Here is the bottom half - it's from a 1990. This is not the same as your 1980 config - similar but not the same...

BigAl1

Thanks Alan. So if I read this right, the control head supplies a voltage to pin 12 on the setting motor, and the sensor string voltage is to pin 4 on the setting motor. I'm assuming the setting motor then has a certain motion based on the voltages it sees on these 2 pins?

Alan

That is all part of the temp loop, the temperature setting is based on the impedances of the combined: control **** pot (+ fixed Rx), the internal sensor and the external sensor.

Alan

BigAl1

Thanks Alan!

brealytrent

..

BigAl1

Ok, how about the following options to update the 928 HVAC control? Looking for feedback on these - pro/cons about each? These are late 90s - early 2000s Ford controls - mainly looking at these because of the vacume control built-in.

Simple 3 rotary **** system, with built-in vacume control. No Automatic temp control, so the resistor variance would need to be worked out to control the temperature setting motor. Might need a remote relay to power the blower fan through the resistor pack.

OR,

Digital version with Automatic temp control, built-in vacume control, funky rotary wheel for fan speed which definately needs a control box for the blower. The whole sensor string would have to be worked out to match with the 928 setting motor, but maybe not as hard as that sounds. Looks like Ford uses a similar temp setting motor with inputs like we have. Later versions of these can have dual AC, but no built-in vacume control, so have to work out the vacume solonoid control interface.

Pics grabbed from ebay.

hacker-pschorr

IMO neither of those offer an "updated" look for the 928, especially the rotary **** one.

Speedtoys

I would argue it cant be TOO updated.

Because it's still a dated total cockpit design.

James Bailey

Is that before or after the wooden Nardi steering wheel ??

Alan

I think you have to look towards german systems to get the right design styling - Porsche would never have come up with anything like either of those.

Perhaps something more like this general type .

Alan

ltoolio

That first one looks like the climate control in my wife's old cavalier.
The second looks updated, but not so much it outside the realm of period appropriate.

MjRocket

I think the 2nd one would look ok as would the one Alan posted.

svpmx83

**** style and layout that may suit but is still modern

Mazda Miata/MX-5




Miata (also available in black *****)



Toyota FT-86 / Scion FR-S

svpmx83

The Potentiometer in the factory HVAC head for the 928 is 200 to 1200 Ohms (2.2k pot using part of the range)