This post from 2002 should help regarding the Escort.
Also message 62470 on the old KL1200LT site at Yahoo should help regarding the GPS. In case you don't have access, here is the message 62470 from January 2002. The clipping problem mentioned is largely solved by turning on the Garmin option to send a beep before it speaks:
If anyone else is creating their own wiring harness to connect a
StreetPilot III to the ComSystem, I just finished and it works.
I purchased the special Garmin power connecter online with a few feet
of cable attached. Using the diagram at the back of the ComSystem
manual, it is easy to find the ComSytem harness connecter with power
and ground to which this cable must connect. To get voice
instructions through the ComSystem, the only minor trick is to connect
only the tip of a 2.5mm mono plug to the AUD wire of the ComSystem
connecter - do not attach a ground.
The SP III voice is clipped a fair bit by the ComSystem but certainly
Now if I get lost because of the bad, bad bike syndrome, I can always
find my way home for dinner.....Barry