switch kit is correct, the jackson is a 3 wire radio which would require 4 wires in the 575 to be used, it should still key without the battery connected as it only powers the mic amp, the battery is switched through the ptt switch but on different set of contacts to the keying circuit, i have seen 2 different types of swich in the 575 and the larger of the two are known to go faulty if they have had lots of use, i would check the cable with a multimeter, if you have a broken wire you can swap it with the redundant rx wire inside the mic and at the plug to get you up and running again