Y-Cable Help


My team was wondering if there was a way to connect 2 motors using a Y cable to a 3-pin slot, since we found online that you can’t use Motor Controler 29s on a Y-Cable.

Where did you find that information? It is incorrect. In fact, that is exactly how you drive two VEX 2-wire motors using a “Y”-cable. Each 2-wire motor plugs into its own Motor Controller 29, and each Motor Controller 29 plugs into the two female ends of the “Y”-cable. Finally, the male end of the “Y”-cable is plugged into a 3-wire port on the Cortex (or PIC, or whatever microcontroller you are using).

it might also be a good idea to plug one of the female ends of the Y Cable into a power expander, and then power one of the motors off the power expander, that way you’re not trying to pull 2X the power from one port, because (I think) if you try to run two motors at full power off one port, each motor will run at half power.

I don’t think this would happen. I’m pretty sure the motors just draw twice the current from that one port. Of course, I haven’t had a lot of training in electricity…

Thanks for the quick response. Me and my team started looking for information online because we tried doing that same procedure, with two Y-Cables, but it did not work (one got really hot and sparked a little).

I considered the issue had to do with one of the Motor Controllers being faulty, but this is not the case, since both motors ran well without the Y-Cable.

As for this information, it doesn’t look like it. I wanted to find this out just in case that was what caused the motors to not move. I found this other thread you may want to have a look at.


What was sparking? Have you tried using a different y-cable or cortex?

Y cables are completely safe as long as their is not more than 2 motors per port, will just draw extra current from the breaker. I would also recommend making sure there are not too many motors on one breaker and that each motor has it’s own motor controller. The motors on the y run just as fast and powerful as any other motor. Also double check that you plug the motor controllers (3 wire) into the y (Female) so that the colored wires line up, not the gold showing wires.

Hello! The best way to use a y cable with a power expander is to connect the two female leads into the power expander itself, then plug the male end into the cortex. This is b/c the y cable will split the power among two motors; however, when wired in this manner you do not lose any power to the mtors. Just remember the motors will have to spin the same way. The easy way to change one motor’s direction is to flip how the connects are plug in.