Randall G.

As I've already written, I have the 993 prefix, 00 suffix CCU installed my car. As does Arjan (check his earlier post), and God knows who else. Perfect compatability, MAX A/C button functions as described in the owner's manual, etc. No wiring mods required, plug and play.

If you own a pre-91 964, you'll have to install the G1-G19 jumper, if you buy anything other than the original (964 prefix, 00 suffix) CCU.

>Second, I checked my PET (ver 5.5) and it indicates;

>1. the 964 659 047 00 is for 964 '90, the 964 659 047 01 is for '91 & later
>2. the 993 659 047 00 is for 993 '94, the 993 659 047 01 is for '95 & later.
>I haven't installed the later Pet (ver 6) and maybe there's an error in ver 6.

Guess you need to update your PET. The above printed from PET clearly shows 964_01 being superseded by 993_00. You might want to call the parts manager at your local P-car dealer, so he can get you straightened out here. Or, tell 'em there's an error in PET, if you really think that's the case. Oh, and tell ANDIAL it's an error, too. When I went to buy the new CCU, they also gave me the 993_00 part number.

Lorenfb

If it works, then be happy. What more can you ask for?

Have Fun
Loren
'88 3.2

Randall G.

Loren,

>Second, I checked my PET (ver 5.5) and it indicates;

>1. the 964 659 047 00 is for 964 '90, the 964 659 047 01 is for '91 & later
>2. the 993 659 047 00 is for 993 '94, the 993 659 047 01 is for '95 & later.
>I haven't installed the later Pet (ver 6) and maybe there's an error in ver 6.

Just checked, and my version of PET isn't any newer than yours. If you don't know this already, you need to click on the color beneath the CCU part number to get the superseding part numbers. Once you get the pop-up display, keep clicking on the part numbers until you run out of superseding part numbers. Perhaps this is what you're missing on your PET?

Adrian

If you have a copy of PET and you think it has a problem please do not contact Porsche because you are more than likely not authorised to have it.
PET has been replaced anyway, certainly here in Europe but of course only authorised facilities have the new system.
Hint hint. May be there is a tad too much public discussion of PET if you get my meaning.
Ciao,
Adrian
964C4

PS: Randalls statement about plug and play for 1991 models and up using the 993 -00 version only applies to factory installed air con in LHDs and to factory installed air con for Japan.
RHD UK deliveries (includes Australia, Hong Kong, NZ, Singapore, Malaysia etc) it is a bit of pot luck. It depends on WHO installed the air con system. A dealer or the factory. Most as I have discovered are dealer installations.

Lorenfb

Per the early and late 964 wiring diagrams, the difference between the
964-00 and the 964-01 is the additional high speed blower sense input
(G1) to the CCU as previously posted. This required the T5 jumper (3-14)
in the later 964 wiring.

The implication based on the PET and the previous posts is that the
964-01 and the 993-00 are electrically the same with the expection
of the second AC button (full AC override). Based on this, late 964s
should have no problem with the 993-00 units. The early 964s will
require the G1 to G19 jumper to update the early 964 wiring.

I generally try to avoid mods and switching units between years
like this because of possible future problems which always seems
to occur. The typical complaint always arises; e.g. "Ever since my
CCU was changed to the newer one, my blower doesn't SEEM as
strong." or "My car doesn't seem as COLD as before you changed
to the later CCU." For the DIY, these changes are O.K., but I have
enough problems without these possible examples occuring.

Have Fun
Loren
'88 3,2

As I said before, "If it works, be happy.".
problems which always seem to occur.