Testarossa A/C blower stopped working mid drive. | FerrariChat

Testarossa A/C blower stopped working mid drive.

Discussion in 'Technical Q&A' started by Threeofnine, Jul 22, 2022.

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  1. Threeofnine

    Threeofnine Formula Junior

    Dec 11, 2020
    393
    Birmingham, AL USA
    Full Name:
    Jarrod Heath
    I have a 1988 TR, US spec. Since I got it the fan on the blower motor has been stuck in the high position, if you try to reduce it just a little it just shuts off. From my understanding this is almost always a transistor issue.

    However, now it seems to have stopped working completely. It’s been unusually hot this summer in my area (100F+). A couple days ago I was on a rather long drive and as I was about a mile from home the A/C and blower motor simply quit working. I checked all the fuses and they seem to be ok. Would this likely be related to the transistor or something else? If someone could point me in the right direction I’d appreciate it.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Check for a burned up main AC +12V power terminal in the k white connector at the fuse-relay panel:

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    Running the cabin fan at full speed actual helps the power transistor (when it's alive) to live longer (since, at full speed, no current flows in the power transistor; whereas, at 3/4 or 7/8 fan speed, the power transistor gets cooked), but full speed puts the maximum thermal stress on that k connector terminal.
     
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  3. Threeofnine

    Threeofnine Formula Junior

    Dec 11, 2020
    393
    Birmingham, AL USA
    Full Name:
    Jarrod Heath
    Thanks Steve, I’ll definitely check that immediately.
     
  4. Threeofnine

    Threeofnine Formula Junior

    Dec 11, 2020
    393
    Birmingham, AL USA
    Full Name:
    Jarrod Heath
    Hi Steve. I checked the k connector and it looks like it’s fine, there is one burned terminal but there is no wire going to it. Odd. See attached photos. Once again, I really do appreciate your help!


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  5. Threeofnine

    Threeofnine Formula Junior

    Dec 11, 2020
    393
    Birmingham, AL USA
    Full Name:
    Jarrod Heath
    Update: Interesting development. After unplugging and replugging the connection, the A/C is working again.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    No, it's not "fine" ;) -- it already burned up so someone has made a modification. What should be there (in the "missing" position) is a large M (brown) wire and a small M (brown) wire. You might have a look around and see if you can find those two wires connected to some other +12V source. Perhaps the modification is something cheesy like just bare ends being twisted together and not soldered or crimped together in a quality way. Very common for Gremlins to come and go with a little wiggling (and removing a connector, or relay, gives everything a pretty good wiggle). Good Hunting!
     
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  7. Threeofnine

    Threeofnine Formula Junior

    Dec 11, 2020
    393
    Birmingham, AL USA
    Full Name:
    Jarrod Heath
    I figured it wasn’t totally fine lol. I’ll do more investigating. Once again, I really appreciate the help.
     
  8. maurice70

    maurice70 F1 Rookie

    Jan 25, 2004
    4,334
    Sydney
    Full Name:
    maurice T
    I may be wrong but I think the 328 has the same setup,
    I recently experienced the same issue where it would only work at high speed, disconnecting and reconnecting the plug connection solved the issue..
    I sprayed a little contact cleaner in there for good measure and haven’t had an issue since.
     
    Threeofnine likes this.
  9. spirot

    spirot F1 World Champ

    Dec 12, 2005
    15,112
    Atlanta
    Full Name:
    Tom Spiro
    I had the similar issues in my 328 with several connectors with burnt contacts, so spliced in line connectors & fuses, usually worked well. The electrical systems of these cars done like all the hot ambient temps - & they are close to 30 + years old ... I think most of the issues with the mid - late 80's Ferrari's are electrical ..
     
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  10. raemin

    raemin Formula 3

    Jan 16, 2007
    2,339
    Lyon (FR)
    Full Name:
    R. Emin
    Silver conductive grease will significantly reduce the resistance of the connector pin.

    Unfortunately I had already replace hundreds of these pins in my car when I was given this advice. After a few trials I came to the conclusion that old connector with silver grease were just conducting better than the shiny bits I had just been crimping for days...
     
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