I know this is probably the wrong section, but does anyone know how to make a harlan 2-step and a transbrake work off of the same button? the 2-step is triggered by a ground and the transbrake works off of +12v. I need them to work at the same time on the same button. any help appreciated.

 

You need to add a relay. When you activate the trans brake button send 12v from the button to the relays. Wire 30 on one to ground and 87 to the two step. That'll do the polarity switch for you. If you want you can add a second relay for the actual trans brake solenoid. Your choice. Some wire their solenoid straight up to the button. Others wire it into the relay instead. In that case, same deal. Just wire 30 for 12v and 87 to the transbrake. If you are using a DPDT relay wire up 87 with the 12v lead and 30 to the transbrake solenoid. That way 87a is not hot when the button is off.