GRTWHT

G'day guys, I've been searching the list so that I can fault find and fix my '81 928's hvac system.
I stumbled across this from John Pirtle's website for 928 S4 service of HVAC System.

My question is, Does my '81 model have this under the centre console? Looks to me in my car that I have the mounting plate, with an earth wire connected, but only 1 solenoid. This lonely solenoid has a red/orange hose and a blue hose connected to it

When I move the bottom slider on the heater control unit to the off position I get a leak. Move it just to the right under the first detent and the leak goes away. You can also hear the solenoid click.
Red I thought goes to the heater (replaced heater valve... no more leaks).
Blue I thought may go to A/C, but cannot find the other end of hose. Looks like it goes out of the firewall into the cowl area and under the heater assy. No mans land if you ask me hey.

I have read heaps on this in the list on the subject so I hope I'm not boring poeple with it by asking.

Any idea on the solenoids would be of great help.

Glenn
'81 928

WallyP

While the 928 was semi-custom-built, and anything is possible, the wiring diagram for the '81 shows six solenoid vacuum valves in the HVAC system. These are pretty well hidden, tucked away forward of the radio, running across the car.

The easier way to test is to find the bundle of colored tubes inside the console next to the driver's right calf. Cut the tubes one at a time (not the black, not the white - start with orange) and test the upper end. If it leaks, plug the lower end until you get a round tuit and can replace the leaking actuator. If it doesn't leak, splice it back with a piece of small rubber or plastic tube and check the next color.

If you will send me an email (not a PM) to techAT928gt.com (change the AT to @) I will send you a paper on the HVAC paper that might help.

The 928 tech info CD set that Jim Morehouse has prepared has a lot of info on the HVAC system, as well as the manuals and wiring diagrams. His email is jim928ATptd.net (change AT to @).

ROG100

Glen,
Do what Wally suggests and get his HVAC paper it will answer all of your questions.

Are you certian that you have a A/C system or the climate control.
There were some differences on the earlier cars.

Good luck,
Roger

Jim bailey - 928 International

I think you may have a manual system no climate control that is on all 78/79 cars and common for Early Euro spec 928s where moving the lever moves a slide that distributes via a vacume manifold on the heater control (lots of little colored rubber tubes) .

GRTWHT

Thanks for your replies to this guys. I will send off an email to you Wally P and ask for the diagrams/info for hvac, thanks for your help.
I guess you are right when you say that the 928 is semi custom built Wally P. I often wonder if their are any 2 cars the same now that they are aproaching 30 years old since production started(still younger than me .
I have a manual heating and A/C system in my car ..... no automatic climate control, it just works off the slider positions like Jim said.

Their is so much to read on this subject on the list, but it seems to me that it will only get sorted by nutting it out myself step by step, bit by bit with the info thats available.
So thanks again for your help blokes and we'll catch ya later.

Regards,
Glenn
'81 928

Tom928

Glenn,

My 81 has the same HVAC console as in the picture.
I discovered that whoever installed the stereo at one time must have tried to force the deck into the console because just behind the deck was a broken actuator vacumm tip hanging from the vacuum line.

Wally's paper is excellent and a must have for troubleshooting the HVAC stuff.

Cheers,

GRTWHT

Yeh Tom, I suspected that the PO replaced the stereo to CD has knoked everything out under their.
Dodgy brothers I reckon. But I have the paper thanks to Wally and I'll be head down but up into fixing it.
Cheers,
Glenn
'81 928

GRTWHT

Well I started working through the paper yesterday and have reached a little closer to having the A/C and Heater system all working as it should.
I'ts alot more enjoyable to repair things when you have all the right info.
Still not completed but thats for another afternoon.

Cheers,
Glenn
'81 928