Clecoed the forward top skin in place to double check wire clearance when the panel is pulled aft to line up the rivet holes. Everything looked good.
Made some changes in the labeling. Printed out transparencies and taped them in place.
Used double-sided tape to tape the cabin heat controller in place to aid in the placement decision. Placement looks good.
Removed the top forward skin.
Removed the IFD440 and its mounting tray.
Removed the connectors from the CO Guardian and the SV-EMS-220 D37. Disassembled both connectors. Reinstalled the wire that I had removed from the SV-EMS-220 D37 pin 31. Routed the wire to the CO Guardian and terminated it with a D-sub receptacle. Inserted the receptacle in the CO Guardian connector. This wire is needed for the CO Guardian to send the CO PPM to the Skyview.
Reinstalled the connectors. Powered up the system to functionally test. Configured the Skyview for the CO Guardian but the indicator still showed a red X through it.
Tried disconnecting the RS232 wires from the CO Guardian to see if that was the problem but the PPL widget was still Xed out.