All of the following wiring diagrams were scanned from the Clymers Collection Series Vintage Snowmobiles Vol 1 book. As I continue to add the actual diagrams for specific models and years I will be deleting these.
SA340-A3 79 Drifter
(generic diagram)
SB440-A3 and later models
79 and later Drifter (generic diagram)
ST440 Intruder (generic diagram)