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Phone/speed sensor mod. Where are the easiest instructions?

Discussion in 'Gen 2 Prius Audio and Electronics' started by Steve Goldenberg, Aug 29, 2004.

  1. Steve Goldenberg

    Steve Goldenberg New Member

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    Where can I find the latest/easiest instructions for the phone/spped sensor mod?
     
  2. efusco

    efusco Moderator Emeritus
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    Steve,
    You'll have to work your way through the posts, but about the place Eisenson starts posting in This Thread You'll find some pictures where he found the speed sensor wires for both the BT phone AND the NAV. They're the purple wires in the right most computer behind the silver vent cover just to the right of the MFD.

    The simplest way to do this would be to divide those wires and attach a simple on/off switch to each one. Drill holes in the vent cover in a convenient spot and attach.

    This will require a very minimal amount of time, the only down side is drilling 2 holes (unless you can find a DTDP switch so you just need one) in the vent cover. Tools will be a soldering iron, a drill, and wire cutters....can't get any simpler.

    BTW, if you do this PLEASE take a lot of pictures. I've got other stuff back there and have used alternate means to defeat those but would love to update my original NAV speed sensor defeat article with these clear improvements. I'd like to borrow someone's photos until I can find some poor sucker to let me do these mods to their car and photograph along the way.
     
  3. Eisenson

    Eisenson New Member

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    NEW INFO:

    There's no reason not to control BOTH functions (nav and phone) at the same time - thus one switch.

    Drill ONE hole in the silver vertical panel or (preferably, though it's more work) in the center display panel with the switch poking out the side.

    Find a submini DPDT switch with no center off, and NOT "momentary". Radio Shack, surplus, etc. This switch connects the center terminals (2 and 5) to either ends (1,4 or 3,6). You want it to control the connection between 2 and 3, and between 5 and 6, simultaneously.

    Bottom view of switch connections:

    1 2 3
    4 5 6

    Ignore 1 and 4.

    Solder 1' wires to 2 and 3. strip 1/2" of the other end, twist together. Solder 1' wires to 5 and 6, strip and twist similarly. Polarity is unimportant.

    Then - find those purple wires. Snip only ONE (either), leaving room to work, and strip the ends. Attach the ends of one of the twisted pairs. Snip the OTHER, and repeat.

    Install the switch in the drilled hole such that when the toggle is in the UP position, everything works. in the DOWN position, you can both dial and navigate.

    A slide switch will work similarly, though it's a PITA cutting a rectangular hole.

    Henry
     
  4. brosnan

    brosnan Member

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  5. efusco

    efusco Moderator Emeritus
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    I think that using just 1 switch for both speed sensor defeats is certainly a good option. But if you just need the NAV defeated, and you use it for an extended period of time you'll lose the 5 minute bars on the consumption screen. Of course you'll lose them with the BT defeat anyway, but I guess I like the idea of seperate switches.

    Also, you may want to access the BT phone, then switch to NAV/MAP screen while you're on the phone (maybe getting directions) and it would be nice if the MAP was at maximal accuracy and not herky jerky as it would be if the speed sensor was overridden.

    Still, if you don't want the dash cluttered with multiple switches the one switch idea is good and of minimal problems. If you have 2 switches you'll have to remember which is which.