Are you saying that the black wires from the solenoid are connected to the ground, and one each of the red wires are connected to M+ and M-? If so, that's not the FIRST-legal way to wire a double solenoid - you're supposed to use either two Spikes, or a couple of diodes in to connect all 4 wires to a single Spike.
Nevertheless, if you do something like this, it should work:
Code:
relay2_fwd = p1_sw_trig;
relay2_rev = !p1_sw_trig;
or if that turns out to be the opposite of what you want, try
Code:
relay2_fwd = !p1_sw_trig;
relay2_rev = p1_sw_trig;