I have the cruise harness with the 4 pin from turn signal stalk hooked up but the car has an additional 3 pin plug from the turn signal switch. Original switch plus one i bought years ago had the extra plug and it said it was for cruise. i'll have to get a picture.
thanks,
mike
Sounds like your turn signal switch has the extra plug for the cornering lamps on C-bodies . Its what the original switch supersedes to via Mopar
Cruise control wiring is a separate overlay harness , it does NOT go thru the turn signal switch itself or its wiring harness