I am working on an RC car, and I need to be able to reverse a 12v circuit that powers my main drive motor.
I have a TIP102 transistor and a 5-30v relay for each motor terminal. I assumed that I could open up ground via the transistor on one side, and the power relay on the other, and then switch these to reverse.
My motor runs each direction when hooked directly to the battery, and my relays are definitely outputting the full 12v, but I seem to have a problem with the grounding circuit. Whichever side has the relay switched on, that transistor gets very hot, and my motor doesn't spin. I tested the transistor and can get it to ground when on a single directional circuit with just the relay on one side and the TIP102 on the other.
Here is my wiring. Can anyone tell me where I screwed up?