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Mondial t blower fan transistor location

Discussion in 'Mondial' started by brettski, Mar 11, 2010.

  1. brettski

    brettski Formula 3

    Feb 29, 2004
    1,754
    north of toronto
    Full Name:
    brett swaykoski
    #1 brettski, Mar 11, 2010
    Last edited by a moderator: Sep 7, 2017
    can anyone offer advice on how to change Part #127014 (#13) on the diagram ?
    is it possible to go through the center vents or is it possible to wire in an
    aftermarket transistor...or do you just have to take out the whole friggin' box ?

    thanks,
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  3. brettski

    brettski Formula 3

    Feb 29, 2004
    1,754
    north of toronto
    Full Name:
    brett swaykoski
    got it...you go through the center vents, drill out the rivets and out she comes...
     
  4. porphy

    porphy Formula 3

    Dec 9, 2009
    1,180
    LouisvilleKY/Switzld
    Full Name:
    Randall Gatz
    Where did you get the replacement transistor?
     
  5. porphy

    porphy Formula 3

    Dec 9, 2009
    1,180
    LouisvilleKY/Switzld
    Full Name:
    Randall Gatz
    I found them at Mouser Electronics. Thanks
     
  6. DavidJ

    DavidJ Formula Junior

    Feb 12, 2012
    385
    Northern NJ
    Full Name:
    David
    Be careful. The OP has a QV. You and I have a "T". I posted about the power transistor last March. The power transistor is in the center console for us. Inside the small plastic box that holds the speed control potentiometer is a small circuit board. The transistor is in that thing. I found it and alternates at Mouser and Digikey. There are other places that have it as well.

    I hope you are doing well.

    Here is my post from last March (never got time to fix this. I'm working way too hard):

    "I suggest you search Fchat for "Mondial fan control" or "TR power transistor" There are many discussions to be researched.
    My problem, and I believe it is a common problem, is the power transistor that controls the voltage to the fan on any speed other than full on or off.
    The temperature is controlled by a simple potentiometer but the fan speed control is actually a small circuit packaged inside a small plastic box. In the 3.2, 3.0 and possibly the 8 (all Mondials) the power transistor is mounted near/in the airflow of the center vent for cooling. In the "T" variant it is inside the plastic box in the center console and is somewhat difficult to replace without removing the potentiometer that is mounted directly above and is soldered to the circuit board.
    There are several alternate transistors the can replace the original, but one must be careful to not over spec the amperage capacity as the linearity of the circuit will be affected.
    All of these transistors are cheap (under $10). I will be trying several types to determine the best solution.
    The original, according to the info I found on Fchat is a 2N3055, 10 Amp.
    There are replacements @20 Amps (2N3772), 25 Amps (2N5886), 30 Amps (2N5301) and 50 Amps (2N5686).
    I think the main problem is heat. That poor transistor is cooking itself in a small sealed box with no chance of air flow to dissipate the heat. I will be experimenting with extending the circuit somewhere into the cabin (hidden of course) to help alleviate the main issue.
    I have just started this process so I can't give you an solid answer or solution...yet.
    I will be targeting the 20 Amp and 25 Amp transistor as replacements."

    DavidJ
     
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  8. porphy

    porphy Formula 3

    Dec 9, 2009
    1,180
    LouisvilleKY/Switzld
    Full Name:
    Randall Gatz
    Thanks for the heads-up David. I purchased the 2N5886G from Mouser. Its the replacement for the 2N5886 which is no longer available. I think the post from bretski clearly mentions that he has a "T". Did I miss something?

    Happy New Year, I hope all is well with you.

    Randy
     
  9. DavidJ

    DavidJ Formula Junior

    Feb 12, 2012
    385
    Northern NJ
    Full Name:
    David
    You are correct. He does mention a T. There are currently 3 threads on blowers in the Mondi section. They are all next to each other and I just merged them in my mind. My bad.
    I might get to the mod I plan on making this spring.
    Good luck with the blower removal BTW. I will need to do it as well, soon. I have a blower fan bearing that is squeaking. Not a good sign. As one of the first to do this, I hope you take lots of pix.

    DavidJ
     
  10. porphy

    porphy Formula 3

    Dec 9, 2009
    1,180
    LouisvilleKY/Switzld
    Full Name:
    Randall Gatz
    Same symptoms as mine. Bearing starts to rattle and it goes up in smoke when you least expect it. Do you have a BMW part number on the blower? If I remember correctly the blower is out of a 1988 BMW 5 series. I saw it in Fchat but I cannot find it now.
    There is always the possibility to have the bearings replaced in the original, but I like the idea of dropping in a new one!
    Cheers, Randy
     
  11. Burch1

    Burch1 Formula 3

    May 26, 2012
    1,028
    Singapore/Carmel, IN
    Full Name:
    Greg
    David,
    Which did you end up using?
    I am getting no flow from by blower at any setting on the pot and suspect it is the transistor below the pot as you describe.
    How difficult is it to get to the transistor and is it a solder replacement?
    Any pics, etc. would be appreciated as I need heat flow here in Indiana now!
    Thanks much,
    Greg

     
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  13. DavidJ

    DavidJ Formula Junior

    Feb 12, 2012
    385
    Northern NJ
    Full Name:
    David
    Sorry, I was so busy with work I never got to replacing the transistor. Maybe this summer?
    My blower works at full speed or off. So with the Ferrari design of the ventilation system being what it is, full speed barely keeps up with the heat or cold. As a result I felt no pressure (pun intended) to make this a priority.
    My plan is to somehow remote mount the circuit board in a location where it can be kept cooler. Maybe I will install a small, slow speed boxer fan on a heat sink to make this issue go away forever.
    FYI the transistor is completely blocked by the potentiometer on the board. It will be a bit of a challenge to get it out. I might have to re-design the whole thing. Might be a bit of work.
    Like I said, not a priority right now for me.

    DavidJ
     

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