Posted 2/10/2018 18:34 (#6568892 - in reply to #6567145) Subject: RE: Agleader 6500 to John Deere 7/8R Starfire harness
In the attached clip from the GPS6500 manual, the page shows the pinout of it's connector. The GPS6500 has 3 RS-232 serial communications ports, and what looks like CAN hi and CAN low wires, which would seem to indicate it is capable of outputting to CANbus.
The next step would be programming to allow the display to look to CANbus for a GPS source. I have my doubts Ag Leader would implement something like that. While it would make for a neater installation in your particular case, their current method is universally compatible with all machines it might be installed on.
I have the means to build a cable to connect a GPS6500 to a CANbus, but I do not have the nerve to experiment with a $2000 piece of electronics.