steering column key light?

Do yourself a favor and download some service manuals

Here

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

More of here

http://www.mymopar.com/index.php?pid=31

Also look around the above site there is all sorts of info

This is right out of the 70 Dart / Challenger manual section 8 (electrical) page 8-100 See? at bottom right?

The lamp connector should be yellow, a single terminal connector, going down to the delay relay. I believe they are normally a round cylinder about ? 3/4" diameter