install caps on heater slide of 928

cal928 · cal928's Garage

My plastic caps were broken when I got my 1978 (928) and I just located 2 new ones. the problem is there seems to be small brass sloted stampings in the panel where the slide levers are that block the caps. how do they attach to the lever

Mrmerlin · 12-11-2010, 01:58 PM

please post a picture,
i can give more info but I need to see what you have

cal928 · cal928's Garage

I will take some digital photos tomorrow and post, but it looks like the tab on part 1a that gets inserted into the slot on the control head is being blocked from attaching to the lever by 2 thin vertical bars on a small brass stamping attached to the front of control lever.

Mrmerlin · 12-12-2010, 05:09 AM

OK I think i understand a picture will confirm this.
You may have to remove the metal sliders out of the panel and cut the small center ribs out to make a rectangle ,so the new sliders will fit, dont damage the metal tabs as they are about 18.00 a piece.
Thats the repair for the new slider knobs

cal928 · cal928's Garage

thanks for your input, it seems logical, attached is a photo to confirm

Normy · 12-12-2010, 03:31 PM

Just stick it in!

[That was a joke] But it is also true. Just push the buttons back in place.

My car had the knobs loose when I bought it. There are fiber-optics cables inside the wires, to lead light to the knobs. Some PO idiot had cut them off. Mine are loose to this day- I might move them once in 3 years, so I don't care. You can take the head unit out and take it apart- it just has bolts, and then the plastic covers separate and it is open right in front of you, and then perhaps you can glue the cut FO wires back in place. If you do this, make sure you do the WYAIT thing and use a pencil eraser on the metal resistance tracks that control the temperature. Clean EVERY contact in there as well! Many times with 928's the contacts on the head unit are bad and it causes the air conditioning to be weak.

Good luck-

N!

Mrmerlin · 12-12-2010, 05:21 PM

Please follow the directions i posted.
You will also need to remove the HVAC head to get the slide springs out a small pair of needle nose will work.
Then trim out the 2 small center ribs of the slide springs and file them flush the new knob will then slide in and snap in place.
You can use a small piece of heatshrink on the wire to assist in holding it in the knob cutout it will be more obvious when you have things apart

Mrmerlin · 12-12-2010, 05:25 PM

to remove the HVAC head,
remove the H shaped trim then the 4 screws on the HVAC Head then the 2 screws on the I bar under it,
they both come out together,
then carefully unplug the HVAC head unit from the 2 harnesses.
Disconnect the battery first

Normy · 12-13-2010, 04:16 PM

And to add to Merlins' posts: If you open the case, make sure you clean your tracks with a pencil eraser! CLEAN all the contacts you can see. This will make a definite difference in how your airco works.

N!

cal928 · cal928's Garage

thank everyone for your help. I have not had time to disassemble it yet, but I do have one question/clarification. You mention a fiber optic cable, does it attach to the plastic cap? see photo of what I have, there is no obvious place for it.

Pete R · Pete R's Garage

Look between the legs underneath. I think there's a hole to slide it in.

Mrmerlin · 12-13-2010, 06:01 PM

the flex cable slides into the center of the knob and also through the inner locking tab and the metal slide spring . use a small piece of heat shrink and small amounts of heat to set it.
The heatshrink will fit about 30mm in from the end of the cable and fit into the recess of the knob

cal928 · cal928's Garage

ok, everything is clear, thanks