Hi Andy,

my factory remote didn't work properly after I hooked up way back because the Ford resistor ladder has completely different resistance values to the Sony remote.
The empeg tuner expects resistances from the Sony remote in the range:
1400 - 54000 ohm
whereas the Ford remote reisistances are in the range:
53.0 to 5108 ohm
and 5108 ohm is the "open circuit" resistance of the Ford remote (i.e. where no buttons are pressed). Only one button on the Ford remote lies even close to the range that the tuner is set up to detect.

What I did by changing the reference resistance in the remote detect circuit is to shift the range that the tuner will detect. It works pretty darn well, if I must say so myself