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New 36v controller (SPD-CT312C1/CT-312C1) + Thumb Throttle (THR-68/THR-101102) = no workie?

Hey All,

I've got an old Razor E300 I've gutted and am trying to cover to 36v.  I purchase 3 x 7.5ah 12v batteries, Speed controller (SPD-CT312C1/CT-312C1)  and Thumb Throttle (THR-68/THR-101102) and I've hit some problems.

First of all, I understand that the thin red wire and thick red wire on the controller should be bridged to turn on the controller on.  But it seems my controller is on as soon as power is applied to the thick lines, regardless of the state of the power switch to the thin line?  Has anyone seen this?

Then, I've tried to get this throttle to work, and no go.  Has anyone successfully used a Hall Effect thumb throttle with this controller?



The CT312C1 power connector's thin red wire is not for powering the controller on and off and is instead the charging line that connects the charger port to the battery pack when the power switch is off. 

Applying +36V to the CT312C1 power connector's thick red wire will turn the controller on and off. 

Here is a wiring diagram that shows how to connect the parts together.

Please let us know if you have any questions.

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Arg!  Thanks for the reply.

Updated wiring for battery/charging per specs and now functions as expected.

But the throttle colors aren't matching up.  In your picture of the thumb throttle, it shows red, black, yellow and green like mine.  But in the works and wiring, that doesn't line up.

Here is how I've mine cabled.

Any pointers?


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The wiring diagram above has been updated for the THR-68 throttle version with red, black, green, and yellow. wires. 

It looks like you have the throttle wired correctly in your photos. When the power switch is on, do all three of the lights on the throttle (power, full, and low) light up?

So I went and pulled in an old project razor dirt bike, and tested the new setup with its THR-48 throttle and it works perfectly. See attached pictures. Any reason the THR-48 works but the THR-68 doesn’t??

And Yes - the LEDs light up on the THR-68 when power is turned on to the controller.

That test points towards the THR-68 throttle not working. I recommend submitting a support ticket to TNC Scooters and let them know that the throttle is not working. 

Thanks!  Done and Done :)

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