Why does my manual transmission 81 k10 have a neutral safety wireing

[hatzie]

The clutch starter interlock switch has a pigtail that runs from the clutch switch over to the Neutral Safety Switch plug at the base of the steering column. Cruise control should add another pair of wires on the clutch switch.

The manual transmission backup lamp wiring is a similar adaptation. It's a pigtail that plugs into the backup lamp switch on the transmission and runs through the firewall to the backup lamp plug that would fit onto the backup lamp switch on the automatic transmission NSS at the base of the column.

Three on the tree has a switch similar to or the same as the neutral safety switch to control the backup lamps.