I finally got around to removing the ACC control unit from my car. What did I find when I disassembled it but that the little pc boards had four fried traces and the PO had done a Mickey Mouse repair. See the picture -- it's gross.
To orient you for the picture -- you're looking down at the board as it is installed in the car. The left connectors are for the temp control and a cable to Nowhere. The right side are connectors for the blower speed pushbuttons and another cable to Nowhere. The pushbutton on the left is Defrost, on the right is Off, the others you can figure out.
I may be able to salvage the board. The added wires are by the PO. In the meantime, I'm mulling over several questions:
1. Are the fried traces the result of a frozen auxiliary water pump? I've never checked to see if my pump works, always assumed it did. Fried trace #4 goes to pin #6 of the right-hand "cable to Nowhere." By any chance does this wire go to the aux pump? I can trace the wire (and will do so when I add an in-line fuse to the pump, tomorrow) but am lazy and would like someone on the forum to answer the question while I get some sleep.
2. Does anyone have a schematic diagram of the ACC? The one on Braingears is illegible. I would appreciate an image or a link to one so I can figure out what the other three broken traces are for.
3. Are these fried traces and amateurish repairs related to my blower speed problem? One would think so -- what do you think? (The blower works correctly in EC mode for all three speed pushbuttons. It runs high speed in Defrost mode, also correctly. However, in the two A/C modes, it runs high speed with the High button pressed, low speed when the Automatic button is pushed, and also low speed when the Low button is pushed. In other words, Automatic doesn't work in A/C mode.)
4. It appears that the board has not been re-soldered. I don't see any cold solder joints (but then, I said that about my cruise board and was wrong). I may put off re-soldering everything until I get these fried traces properly rewired.
Interesting how everyone's ACC problem is slightly different!
Jeremy