Author Topic: Thumb Throttle kill switch  (Read 6273 times)

Offline Bikewrangler

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Thumb Throttle kill switch
« on: March 11, 2020, 03:03:48 PM »
Hi all. Opened the thumb throttle to install a kill switch. That is the throttle has no effect when stopped by po po.
Seem to have one green, one white and two black wires going to the potentiometer. What is the "best" wire to install a kill switch on? (just want the throttle lever to not work, but lights work as usual).
What wire is the signal to motor?

Thanx for any input.
Cheers
Jim
GM5

Offline Bikewrangler

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Re: Thumb Throttle kill switch
« Reply #1 on: March 11, 2020, 03:12:04 PM »
As I google my way tru I come to the conclusion that the green wire is the throttle signal...?
GM5

Offline Bikemad

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Re: Thumb Throttle kill switch
« Reply #2 on: March 11, 2020, 04:43:36 PM »
Hi Jim,

You can install a switch into either the Green or the White wire and it will disable the throttle when the switch contacts are open.
One is the throttle signal wire (probably Green) and the other will be the +5V supply to the throttle Hall sensor, so adding a switch into either circuit will work.

You can use a small steel pin or needle to pierce the wire insulation and then use a voltmeter to check voltages in relation to ground (Battery -) if necessary.

The Black wires are ground wires for the Throttle Hall sensor and the battery gauge. Placing a switch in this wire is not a good idea.  ::)

Alan
 

Offline Bikewrangler

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Re: Thumb Throttle kill switch
« Reply #3 on: March 11, 2020, 05:12:46 PM »
Yep. Can confirm that the green is the signal. Robust however is not the word that comes to mind when tinkering with this. The tiny tiny amount of white gue holding the wires into the "throttle mechanism" came promptly off and the whole "pin in throttle hole" fell out -  :'( - Got it back in.. and the kill switch works like a charm, but now I got to find suitable "non conductive" gue to hold it in place. Getting my hot glue gun in there without damaging more is going to be a monstrous task. Guess I have to get some hot glue on a toothpick (after a shot of vodka) and hope I can hold it steady enough to hold this together.  :-\

More pics are coming when/if I get this "right".
GM5

Offline Bikewrangler

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Re: Thumb Throttle kill switch (hidden)
« Reply #4 on: March 12, 2020, 10:22:27 AM »
Recipe for hidden kill switch for throttle.
1) Popp of the grey top on the thumb throttle (gently). You want to add some hot glue to the
cubby hole where the wires to throttle handle go down into (the white gue there is "no good", carefully
remove it with tweezers whilst holding the wires/sensor in place), hold your glue gun above and drop
a drop or two there (see pic), then almost immediately hold the throttle case up, so that the hot glue
do not run into and down the sensor, whilst blowing gently on the glue to make it set faster and spread to stick to surrounding plastic.
GM5

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Re: Thumb Throttle kill switch (hidden)
« Reply #5 on: March 12, 2020, 10:58:31 AM »
2) Get a micro 12v switch (that will fit into your handle bar, or grind one like I did to make it fit).
Get the switch wired. Push on the wires going into the throttle case so the loom set with zip tie comes out.
Again very gentle. Behind the wire loom space (after holding the wire loom end to the side), drill a hole.
Best way is to first remove the alu ring that fits around the handle bar (unscrew the lock pin, then wiggle
the ring out. Drill hole in thumb case from inside.... gently. Then drill hole in alu ring, make sure you drill in same place :) - Put it back together, find position for throttle on handle bar, drill hole in handle bar. Slide throttle back on handle bar, align the holes. Thread a 12v wire in thru hole (tru case of throttle, and out tru handlebar). twist the wires from switch onto your "guide" wire and pull the wires tru handlebar and up into throttle case (back and fourth until it comes up). Twist one end of switch wires to one end of the green throttle signal wire, and the other onto the other end of green signal wire, slip shrink tube over the twisted wires (if you solder this it will be a pain to fix/repair). Use hot hair gun to shrink the tube on the twisted wires, to heat with solder gun you run the risk of burning something that you do not want burned or melted. 4-5 sec with hot air gun is enough and blow sideways, not straight into the case.

3) Gently pull the wire loom out again (hold case and wiggle/pull) on the main loom wires from outside the case,
so that the loom end inside the case goes back to it`s original position, then gently tuck the new wires into same space. Pop the grey top (with battery lights) onto the case.

4) I used a bottle cap on the back of my 12v kill switch (so that the switch don`t disappear into the handle hole).
Put some glue on the cap and pushed cap and switch in (do this fast enough so you don`t end up with a switch protruding  way out) - mine ended up a bit more "out" than I wanted to :(

5) slide on your holks (dunno the English word) the soft grips at each end of your handlebar :)
Cut a piece of rubber (from and old tire) to fit the hole at the end of the handlebar over the switch. If yoy measure right it should fit snuggly and stay there on it`s own, you can also dap a small drop of super glue onto the switch cap and stick the rubber cover on, be careful not to glue the switch in... Or glue a bit on the rubber so it is glued to the slip on handle grips.

6) Bob`s your uncle!

NOTE: this is pretty much a permanent set up. Do not complain to me if you have to buy a new throttle and handlebar :)
GM5

Offline Bikewrangler

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Re: Thumb Throttle kill switch
« Reply #6 on: March 12, 2020, 11:03:16 AM »
Use thin enough rubber for a end cap so that the switch will work.
GM5