jschiller

Thanks, Dave. Good advice. I will drop back to square one and start over and replace the mentioned components. We are soon to be in the non-A/C season here and it will make a winter project.

worf928

The nuke-it-from-orbit approach is usually the fastest least time-intensive path to A/C nirvana. A new compressor is roughly $400 and the various expansion valves, o-rings, and r/d are maybe $250. Compressor hoses is where it gets scary. You don't list your 928 model so I don't know what compressor you have. New barrier hoses for the 6-cylinder compressor are available from Griffiths are reasonable cost. For the 10-pot compressor (90+) you will have to seek out a rebuilder if your hoses are not barrier hoses. You don't even want to ask the price for new Porsche barrier hoses. If you already have barrier hoses then count your blessings.

The rest is 'just' labor.

If you've got a good vacuum pump then you should be set. The only remaining variable is if the system is contaminated with something other than gas (e.g. liquid or solids) in which case you'll need to acquire a DIY system for or outsource service for flushing.

jschiller

It's an 89 S4 so it ...should....have the old style compressor. The PO converted to R134 in 2004 (I have all the receipts) shortly after he bought it from the original purchaser. The compressor and receiver/dryer were replaced and he was charged for "oil and fittings" of unknown type. Later the rear A/C was worked on that included a recharge. I don't see any other work done on the system except one more recharge. Presumably it has worked satisfactorily since then. He sold the car in 2017 to the guy that flipped it to me.a week ago. So it is essentially a 2 owner car up to me.

Davin-az

Hi. I have 83 928 the ccu is dead. I have power to all of the relays and fuses are fine. Resister pack is new. Blower tested good. My 928 has manufacturers date of 4 of 83. The vin says it takes the later ccu thats in it 83.5 to 95. The original ccu was na when i got the car.
is there a way to tell by the wiring which ccu should be in it?

Mark Anderson

The early 83 uses the 05 head unit that has 3 connectors going to it. The later 83’s have only 2

Davin-az

What year is yours?

Mark Anderson

Those pictures are from a 1981 928 but it is the same unitl early 83. We have rebult units in stock for all the applications

Davin-az

ahhh ok. Good insight my plugs are the same with the same wiring configuration from your photos but the head unit i got is from an 95. Same plugs but must be different wiring. No wonder i can't get it to work. I will order one. Thanks.

Mark Anderson

if you look closely at the late head the circuit board does not have any contacts on the right side

Davin-az

Damn your right!!! The more you know!!! Very easy way to tell!

Wisconsin Joe

You're new here.

Mark's cars are all years. He runs 928 International, one of the best sources for used parts for us.

He knows 'just a little bit' about the cars & the differences between the years.