355 AC control panel failure? | FerrariChat
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355 AC control panel failure?

Discussion in '348/355' started by J. Salmon, Apr 4, 2010.

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  1. J. Salmon

    J. Salmon F1 Rookie
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    #1 J. Salmon, Apr 4, 2010
    So I drive my car after redoing the sticky bits and realize now that the AC panel is not working correctly. I have fan speed, and the stop button. No AC, no heat, no vent control, and no auto anything. I have checked the 10A AC fuse in the footwell. I did not disconnect the battery when I took it out, and I have unplugged and replugged it several times during the process.

    Is there something else to check, or is the board fried? Any suggestions? Thanks, as usual.
     
  2. eulk328

    eulk328 F1 Rookie

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    #2 eulk328, Apr 4, 2010
    Last edited by a moderator: Sep 7, 2017
    I would triple check the connections. There's really not much to go bad on the temp control panel. It's mostly switches, resistors and some diodes. The "real" climate control electronics are in an ECU located elsewhere.

    I believe the blue disc thingy is a protective device... can't remember now what they're called. Still, if it is a protective device I'd be surprised if it went bad. Are you sure there isn't a second fuse somehow connected to the climate control system? A 10 amp fuse seems a bit small to handle everything (blower fan, A/C clutch, water valve, ECU etc.).
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  3. J. Salmon

    J. Salmon F1 Rookie
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    #3 J. Salmon, Apr 13, 2010
    Tom at Sport Auto did determine this was the failure. Stickynomore to the rescue again with a replacement.

    I thought this was interesting:
    With the bad board plugged in, I got no heat, no AC.

    With the board OUT (nothing plugged in) I got medium fan speed, standard vents, and automatic climate control on a reasonable temperature setting. I drove the car this weekend with the top off. When I started it was cold and I got nice heat out of the vents. When I pulled in, it had warmed up and the AC was working just fine.

    So: if yours dies, just unplug it you will have a reasonable setting as default, fix at your leisure.
     
  4. flyinlo

    flyinlo Karting
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    #4 flyinlo, Apr 13, 2010
    Have you disconnected the battery since replacing the AC panel? I did the same thing with the same results. Thinking it was the ECU I found one from a parts car and plugged it in and it still didn't work. I turned off the battery cutoff and then back on, and after rebooting the car everything worked. If that doesn't fix it, let me know. I've got an AC ECU that is probably just fine sitting on a shelf...
     
  5. J. Salmon

    J. Salmon F1 Rookie
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    #5 J. Salmon, Apr 13, 2010
    I sent the AC control panel to Tom and he plugged it into another car. It had the same issues there as I was seeing in my car. I did not unplug the AC ECU (under the front bonnet). I think since everything seems to work fine without the control panel installed, the ECU must be working.
     
  6. eulk328

    eulk328 F1 Rookie

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    #6 eulk328, Apr 13, 2010
    Are you keeping the old panel? Might be easy enough to troubleshoot the problem.
     
  7. J. Salmon

    J. Salmon F1 Rookie
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    #7 J. Salmon, Apr 14, 2010
    New panel works just fine, and I will sleep easier tonight. Don't know what happened.
    As in the picture above, the thing looks to be about as high tech as a high school electric project. It can be fixed, but the price was some $500ish to do it. I did keep it, and if I find a better option I will fix it for a spare.
     

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