WE WORK ON A NAVY HERC PRIOR TO 165. OUR PLANES HAVE THE LONG WIRES FOR HF ANTENNAS THAT CONNECT TO THE VERT STAB TO THE FORWARD OF THE FUSELAGE. HER IS THE GRIPE, HF 2 COUPLER FAULT LIGHT COMES ON WHEN YOU KEY THE MIC. HF 2 WILL NOT TRANSMIT NOR RECEIVE. IF THE MIC IS NOT KEYED AND THE TEST IS INITIATED ON THE CONTROL HEAD THE RT LIGHT COMES ON. WE HAVE SWAPPED COUPLERS, CONTROL HEADS AND R/TS WITH THE GRIPE NOT FOLLOWING. CHECKED THE COAX RESISTOR BUT HAVE NOT CHECKED THE HF #2 RELAY. WE HAVE CHECKED A NUMBER OF WIRES ALL READING GOOD. ANYONE HAD THIS ISSUE BEFORE OR HAVE ANY POINTERS TO GIVE ME. I WOULD APPRECIATE ANY HELP. THANKS.