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Window Schematic Understanding?

Discussion in '308/328' started by twright, Dec 25, 2009.

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  1. twright

    twright Karting

    May 15, 2005
    225
    Indianapolis USA
    #1 twright, Dec 25, 2009
    I am having difficulty understanding the schematic for the power windows. I downloaded the wiring diagrams from Bullfighter's web site (Thanks, Bullfighter!) and trying to understand how the windows work.

    My windows work very poorly (Don't they all at some point?) and I'm currently working on them. I'm cleaning up the internal wiring and mechanical stuff, but how does the circuit work?

    The system only has a relay switch and a motor. Normally, in a circuit like this, the relay would be between the switch and motor so that the high current would be isolated from the switch. But in this diagram the switch is between the relay and the motor!

    How does this thing work and why is there a relay?
     
  2. twright

    twright Karting

    May 15, 2005
    225
    Indianapolis USA
    #2 twright, Dec 25, 2009
    Unfortunately, I have confused my B members. I should have given credit to BIRDMAN, not Bullfighter for his schematics. Please forgive me.
     
  3. AZDoug

    AZDoug Formula 3

    Jun 17, 2009
    1,606
    Along the Verde , AZ
    Full Name:
    Doug
    #3 AZDoug, Dec 25, 2009
    That is why the windows work slow.

    The switch is some sort of double pole, double throw switch that simply reverses the current and ground wires depending on which way the the switch is thrown.

    I guess a relay somewhere is better than no relay at all....

    The Italians have funny ways of wiring things, I think they learned it from the English.

    Some people here have made their own relays systems inside the doors, that gets power from new heavy gauge power wires run into the doors also.

    Doug
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,825
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Dec 25, 2009
    Last edited: Dec 25, 2009
    (Assuming that you are looking at a stock schematic) No, in the stock '70s-'80s F configurations, the full window motor current passes thru the window switches. The aftermarket "window accellerators" usually add a relay between switch and the motor (but also requires running a high-current capable wire from a good +12V source to supply the juice as Doug mentioned). The stock window relay is there just as a way to make the windows only operate when the ignition key is "on" but without also passing the window motor currents thru the ignition switch contacts -- i.e., the window are a "key-controlled" item.
     
  5. Paul_308

    Paul_308 Formula 3

    Mar 12, 2004
    2,345
    #5 Paul_308, Dec 25, 2009
    Last edited: Dec 25, 2009
    Simple: Relay's function? To enable circuit only when ignition key is on.
    Motor turns one way to raise window which is connected by a cable to keep it level. Motor gets to end of travel tripping motors internal overcurrent breaker stopping the motor. Switch reverses voltage to motor to reverse direction of travel. All the logic is in the window switch.

    You assume Italians race car designers think like you do.

    Real world - The gearcase grease cakes up. Window guides get stiff. Motor working hard demands more current. Years of abuse cause contacts at ground, at switch, at connectors, at fuse, to increase resistance, dropping more voltage, depriving motor.

    Fix - Thoroughly clean and regrease system. Change fuse panel and add one or two relays in door to eliminate voltage drop. Read BOTH pages of this thread - http://www.ferrarichat.com/forum/showthread.php?t=229991 especially CRALLSCARS post at the end.

    Results- http://www.ferrari308gtbi.com/windo.wmv

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