Louis,
If you have the -AJ and a 1970, you have side MARKER lamps; in late 1969 production sometime after VIN's past 11000 they changed from reflectors to markers. These plug into the headlight back, that's how they source power. I think the -AN might not have this recepticle for the plug. This isn't the end of the world; you can do a cut and splice for power, OR you can get these ScotchLok connectors and rig something up pretty quickly.
Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored