1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Power Window Relay Setup

Discussion in 'Automotive Electronics' started by John Salla, Mar 20, 2015.

  1. rfranzk

    rfranzk Member

    Joined:
    Dec 19, 2011
    Messages:
    92
    Likes:
    4
    Hi John,
    Glad to hear your up and running. I was thinking with one Double Pole Single Throw switch you could disable the rear windows on both sides by open circuiting the ground and V+ between the relay and the motors (wires from terminal 30 to the rear motors) and engaging them only as needed. The switch contacts would have to be rated high enough to carry the motor current.
    Thanks,
    rfranzk
     
  2. John Salla

    John Salla New Member

    Joined:
    Mar 20, 2015
    Messages:
    27
    Likes:
    0
    Hi Guys,
    Can we please revisit this posting?

    I wired my car according to Mike's diagram but I useed two relays for the driver's side front window and rear window and two relays for the passenger side front window and rear window. After I put the car all back together (I know this was foolish and I should have thoroughly tested before I did it) I tested the windows, and when I pressed the switch to maked the driver's side front window go up, at the same time, the driver's side rear window went down without me pressing the switch for the rear window. Same was true for the passenger side. I am attaching a diagram of how I wired in the two switches for each side of the car.

    So I have a problem. Now one could say why don't you just add four more relays. If you read my postings, I am really pressed for space. Secondly, I really don't want to take everything apart again. This car is a bear to take apart and put back together. I was thinking is there some way I could "turn off" the ground to the other window when I am operating one of the windows hooked up to two of the relays? I hope I am making sense. If you look at the attached diagram, when you press the button on the switch, what happens is a ground is completed and the window either goes up or down. In my case however, two windows are being activated, one in one direction and the other in the other direction. So if there is an easy way to prevent the ground for the window that one is not pressing the button, that would solve the problem. Or maybe I could install throw switch that would determine which switch has the ground. I don't know. I am just trying to think of something simple. Or maybe I can change the kind of switch I am using. That would be the easiest.

    Maybe, nfranzk has given me the answer above with a double pole single throw switch. What do you think? Is this my answer?

    In any event, I would greatly appreciate your help.



    John
     

    Attached Files:

  3. MikeMl

    MikeMl Well-Known Member Most Helpful Member

    Joined:
    Mar 17, 2009
    Messages:
    11,041
    Likes:
    541
    Location:
    AZ 86334
    I'm puzzled. You have two switches (front door and rear door). You have two motors (front door and rear door).

    Presumably, you wired the front and rear motors in parallel?

    You wired the front and rear switches in parallel as shown on the drawing.

    If so, then either switch always moves both front and rear motors simultaneously. Nothing you can do about without adding more relays. Remember, you added relays to handle the motor current, so you cannot pass the motor current through the switches.

    If you cross-polarized the motors, one would be going up while the other is going down. If polarized the correct way, both windows go up or down respectively.
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. John Salla

    John Salla New Member

    Joined:
    Mar 20, 2015
    Messages:
    27
    Likes:
    0

    Mike,
    I have a total of four windows, four motors, four switches, and four relays. I used two of the relays for the drivers's side and two for the passenger side. I guess I cross- polarized the motors. Let's just talk about the driver's side. Two windows, front and back, one switch for each, one window for each. I thought if I used two separate switches I could operate the front and back windows separately, but I found out otherwise today using the 5 pin switches I have. From what you are telling me, there is no way to operate the front and back separately without adding more relays.

    For a moment, I thought maybe if I purchased and used a double pole single throw switch to control the rear window through pin 30, but on second thought that won't work since when you operate the rear window the front window will still move.

    Maybe having the front and rear move simultaneously on the same side is not so bad, but now I have one up and one down and I would have to straighten that out if i went that way. I guess to eliminate the cross polarization I have to reverse the wires on one of the motors, right?

    Thanks for your help.

    John
     
  6. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

    Joined:
    Oct 30, 2010
    Messages:
    9,906
    Likes:
    1,094
    Becauseone window is going up and the other down, you have to switch the motor wires on the one errent motor. The one that moves counter-intuitively to the switch.
     
  7. MikeMl

    MikeMl Well-Known Member Most Helpful Member

    Joined:
    Mar 17, 2009
    Messages:
    11,041
    Likes:
    541
    Location:
    AZ 86334
    Here is how to do it with three relays per side. I am assuming the simplest center-off switches. Yours may be complex enough that you could eliminate D1-4, but I dont understand them (and I think, neither do you) . This way, you only need three connections to each switch.

    I labeled what each relay does. If moving the front window, only up or dn are activated. If moving the rear window, both up and rear or dn and rear are activated.

    43.gif
     
  8. John Salla

    John Salla New Member

    Joined:
    Mar 20, 2015
    Messages:
    27
    Likes:
    0
    Mike, thanks so much for the new diagram. I will need some time with it to understand it and how everything works. I appreciate your taking the time.

    John
     
  9. MikeMl

    MikeMl Well-Known Member Most Helpful Member

    Joined:
    Mar 17, 2009
    Messages:
    11,041
    Likes:
    541
    Location:
    AZ 86334
    There are four "switch contacts" in the diagram. Pretend that any one of the four are closed; the other three are open. Any given switch activates one or two relays; trace out how? Current flows only from from anode to cathode in a diode.

    Depending on which relays are activated, which motor runs? and which direction is the current going through the motor?


    ps: I just noticed that there is a minor error in the diagram. If you can find it, it will show that you really understand it. Yank my chain before you try to build it, and I will tell you what the minor change is...
     
    Last edited: Mar 31, 2015
  10. bwilliams60

    bwilliams60 Member

    Joined:
    Jan 11, 2015
    Messages:
    38
    Likes:
    0
    Location:
    Canada
    That would make for an interesting event if wired up as such! Did you run this on the simulator as well? That would be a good one for my students to figure out. Thanks MikeMl.
     
  11. John Salla

    John Salla New Member

    Joined:
    Mar 20, 2015
    Messages:
    27
    Likes:
    0
    I am still going with the four relay setup with one switch moving the driver's side front and rear windows up at the same time and down at the same time and the same true for the passenger side. The problem is the rear window goes up and down faster than the front window. So not to burn out the rear motor, I am thinking of putting in a DPST switch so that I can turn off the power at pin 30 of the relays for the rear windows after they have completed going up or down as the case may be. I am attaching Mike's diagram with these switches drawn in. I have two of these switches rated at 10 amps dc. What do you think? Will it work? Is it a good plan? Is there a better plan?

    Your counsel and advice is much appreciated.

    John Scan_20150404.jpg

    P.S. How do you run it on a simulator?
     
  12. MikeMl

    MikeMl Well-Known Member Most Helpful Member

    Joined:
    Mar 17, 2009
    Messages:
    11,041
    Likes:
    541
    Location:
    AZ 86334
    John, what is the current rating of the added switch? A SPDT switch would select front or rear motor, like in the three-relay circuit I posted.
     
  13. bwilliams60

    bwilliams60 Member

    Joined:
    Jan 11, 2015
    Messages:
    38
    Likes:
    0
    Location:
    Canada
    Can you post a picture of the switches and relays you are using? Is this all stock equipment in this car or something you have added on?
     
  14. John Salla

    John Salla New Member

    Joined:
    Mar 20, 2015
    Messages:
    27
    Likes:
    0
    Mike,
    The added DPST switch is rated for 10 amps. It would only be attached to pin 30 on the rear window motor so that I can turn off the current on the rear window motor after that window has fully went up or down as the case may be while the front window still is going up or down as the case may be. As I said, the rear window goes up and down faster than the front window. So lets say you want to put both the front and rear windows down all the way. You would press the window switch down; both windows would start going down; the rear window would get down all the way before the front window, I would then hit the DPST switch which would turn off the current at pin 3o to the rear window; I would then keep pressing the window switch until the front window got down all the way.

    As requesting, I am attaching photos of the window switch, the Bosch relay, and the DPST switch, all of which I purchased after market. Bosch relays.jpg DPDT window switches.jpg DPST switch.jpg
     
  15. MikeMl

    MikeMl Well-Known Member Most Helpful Member

    Joined:
    Mar 17, 2009
    Messages:
    11,041
    Likes:
    541
    Location:
    AZ 86334
    I would just wire the new switch to select front or rear motor as I showed the third relay doing. If you want only the driver's window to move, first put the switch to select the front motor, and then use the jog switch to move it. That way the rear window stays put. I'll bet that this is the mode you will use 95% of the time.
     
  16. John Salla

    John Salla New Member

    Joined:
    Mar 20, 2015
    Messages:
    27
    Likes:
    0
    So you are saying get a DPDT toggle switch and tie that into pin 30 and use that to select front or rear motor and then use the window switch. Yes I think I understand how that works. Great idea. Thanks much.
     
  17. MikeMl

    MikeMl Well-Known Member Most Helpful Member

    Joined:
    Mar 17, 2009
    Messages:
    11,041
    Likes:
    541
    Location:
    AZ 86334
    SPDT is sufficient. Only one end of the two motors need be selected; other end of the motors can go to the same relay contact. Performs the same function as U3 in the three relay diagram.
     
  18. BibaResto

    BibaResto New Member

    Joined:
    May 23, 2016
    Messages:
    23
    Likes:
    0
    Location:
    Irwindale, CA
    I just want to be able to find this thread again.
     

Share This Page