It's always best to have both positive and negative cables going directly to the battery.
If you ground to the chasis, it has to ground through the frame, and any ground cables to find it's way back to the battery to complete the circuit. Finding resistance all along the way.
What you most likely have going on, is a miss wired solenoid (it is a China made nock-off). Check your wiring diagram that came with the winch. Or better yet, google a Warn diagram. The colors may be different, but all the wires need to go to the same locations.
Is also possible to have a short in your remote ( it's trying to go in and out at the same time). Do a continuity check on the remote.