Even though we don't have the firewall foward harness you can turn on everything else by grounding the relay that the diode attaches to. Just ground your battery, then alligator clip the "diode post" to the airframe. Everything comes on. Of course the fuel pump comes on as well but you can pull the fuse so you don't have to listen to it. But it gives you a chance to work with your radios, intercoms, etc.