I removed my dash to replace the heater core, upon reassembly. I found 3 plugs that I cannot find mating connectors too. Left Dash 1a and Left Dash 2 and Left Dash 2a are under the Dash to left of the steering column, kind of near the big square box connector. Right Dash connector is behind the glove box. If anyone can help me figure out what they are I would greatly appreciate it.
2000 Blazer LS 2WD 4DR 6 Cyl
pics should be attached

 

They are probably for options that you don't have.