Help please

[Hound01]

I have a electrical plug and possibly a vacuum line that I need identification as to where or what they are for, the electrical plug is located kinda behind the distributor on my 1984 c20 , see the attached photos and the last photo is what appears to be a real small plastic tube coming out of the fire wall plug but it’s been broken off so I have no idea where it hooks to any help would be greatly appreciated

 

[Ricko1966]

The vacuum tube is vacuum for the heater controls. Look for a vacuum reservoir to hook it to or tee into a line going to it. The electrical connector I need a better view your thumb is covering most of the connector.

 

[Smtty58]

Was that truck originally a 6 cyl? Looking at my Haynes V8 wiring diagram, I don't see any yellow wires on a 2 wire connector. On the 6 cyl. diagram there's a connector with a yellow and pink w/black for a speed control switch. You could also dig around, maybe even here, for the GM diagrams.