Steve Pratel

OK, the issue was the range of my Multimeter I am getting 15K on Interior and Exterior, but still getting an open circuit for the Mixing chamber. I'm done for the day, will see what tomorrow holds. It is Bourbon time............... Really appreciate the help!

I think given no blown fuse for the AC compressor clutch, and everything testing out, that I have no hard/dead unfused shorts and I can drop a new CC unit in without worrying about it burning up. Now I need to run down the Tachometer issue. I really can't complain though EVERYTHING else works perfectly..... Well, except for the Micro Switch for the key at the rear hatch ;-)

Donkeychobo

Ok, looking good so far then.
sensors are.
1. On the side grill vent of the fan blower below the wipers. Under the hood
2. small round vent on dash, follow the tube behind down to the sensor
3. Look into the main centre dash vent, its on the end of a cable and clips on.

Not sure which micro switch in the rear you are having issues with. The one for the boot/trunk light is on the bottom of the hatch strut.

Rob

Steve Pratel

Yes, I'm referring to the Microswitch for the rear hatch. The momentary switch has failed. I have a new O Ring and Switch, am waiting for warmer weather to tackle it.

Steve Pratel

I ordered a new Climate Control Unit. Considered a used, but I dont want to continue to tinker and replace parts, or buy one used for $3-400 only to have that fail in a year or two. The FPR and FPD, Tach and Climate Controls were all unplanned expenses, and have displaced/delayed the suspension refresh.

Will report back when I get the part installed and tested.

VAROOM77

Thanks for the detailed info on replacing the HCV chip. You also mentioned some companies repair aftermarket....?? I would like to query these companies, if can send list. Porsche wants $1100 for new control unit!!!

Thanks much! I am original owner 87 944, actually ordered it from Porsche dealer in Frankfurt and picked up at factory in Stuttgart 5months later!! So, difficult for me to sell, but probably should.

Cheers and Thanks!
Rick Gentry
VAROOM77
gentryrb@aol.com

Steve Pratel

Wanted to report back. I ordered and received the new climate control unit.

Installed it last saturday, charged the cooling system, and have gone on several drives testing everything, and it all works perfectly. All flaps, diverters, from recycle to floor and defrost, max defrost, and all AC works. Easy to control temps, AC blows cold, and heat is HOT. **Tell you what, in 50 years of driving everything short of the exotics, I have NEVER had an AC compressor engage so quietly. I was laying under the car, the compressor a foot from my head and I did not hear it engage for the first time. How I knew was that the pressure on the R134 gauge dropped suddenly. I heard NOTHING. Looked at the compressor and saw it was engaged. Confirmed this with several cycles. WTG Porsche............. The system sat 10 years, so I added a can of 134 with sealer, then 2 and 1/2 cans more to get to the bottom line of the green. Will circle back to it this weekend.

I was concerned that there was a short or issue in the system that I couldn't find, and that the new unit would fry, but this is third drive and almost 100 miles with it in and all is good. Seems my diagnosis of a failed and shorted capacitor was correct. Now I hope my assumptions on the Tach are correct. Just waiting for that puppy to get here and installl.

Thanks for the help al!