Today I fabricated the bussed resistor array needed to use the GP1, GP2, GP4, and GP5 pins as discrete inputs. I used a small piece of protoboard and cut it to size. I then soldered 4 resistors to to common trace on the board. The independent ends of the resistors were then soldered to the board. The resistors are 5K .1% 1/2 watt flameproof resistors. I spoke to Garmin about the specs and they initially recommended 1/4 watt resistors but I pointed out that up to 20ma can be sunk from each input. This current draw at 12 volts would yield 240 mw, which would be right at a 1/4 watt resistor's limit...they then recommended going to a 1/2 watt resistor.
Next, a #22 wire was soldered to the common trace and the opposite end terminated with a D-Sub female socket. This is the GP +12v (pin 50) on the GEA24 connector.
Finally, I soldered each individual GP pin to the independent side of each resistor.
The array was then covered in double wall heatshrink and all wires labeled.
