1988 928 Air Conditioning Issues/Questions

[Dwsewell]

I need some help with my 1988 928. The air conditioning works intermittently. It works when you click the "AC" button on and off a couple of times. There isn't a certain number of times to click it. Sometimes it works right away, sometimes it takes a while. The air seems to blow cold once it works.

The car does seem to run hot when the AC is on. It has been 90+ degrees each of the last two times that I've taken it out. When you turn the air off, the engine does cool back down. The engine fans are both working and I've opened up the slats manually so that the radiator is getting air continuously. The slats do have a row or two that are broken so if anyone has a source for instructions or a video on how to change them out I'd appreciate it.

Lastly, can anyone tell me if the air conditioning takes good old fashioned Freon or the has been converted to the new air system. I've attached a picture for reference.

[aluminum]

Here is a good link that may help :
Freon capacity for '88 S4? - Rennlist Discussion Forums
R12 is what most often is in them unless converted already
( Often found in Craigslist by the way )
Your second Port for the gauges " Hi and Low side " is in the Line along the Passenger side
fender well toward the front just under the air intake tube , just remove it to see .
Is a Low Pressure Switch behind the grill where you took your Photo . Has 2 Wires under a rubber Cover , just pull the rubber back .
Jump the wires to see if the compressor runs when jumped .
If so then that's most often a sign of Low Freon
Find the adapters to hook to Gauges to the 2 ports . You can get the Gauges Free on the
" loaner Program " at Auto Zone ( just return for your money back about $140 )
You well need the correct Pressure for Low and Hi ports at your outside temperature.
If it well not take the freon when running the motor and the compressor is not turning the jump the switch to make compressor run as you add freon .
If the Low side say is normal like perhaps 45 / 50 Lbs but the high side is low then close the Low side Valve on Gauge set and slowly open the high side watching the Gauge .
You should get the High side up that way
Other Note's :
Inspect for signs of leakage . Look for what looks like Oil leaking on rubber hoses or metal Lines . This well be the mineral Oil leaking from Hose or blown seal .

If you have pressure most likely you can service the Car AC without replacing the Dryer and a lot of work like Vacuuming the system out and such .

Personally I would get the Gauges on it and take a reading .
I would Clean all electoral Hookups like on the Compressor and switches .

Your Heating and venting must be set properly for the Air Con to come on also

? Perhaps this well help some

In Vegas House just now