Gary, on the 740i '93 the plug is located by the brake pedal mount under the dash. It is located about 5 inches to the left of the mount.
I don't have an actual picture of it, but it should be a 12-pin connector with a single pin next to it.
I hope this helps. I installed one on my 750iL that I got from www.bmwalarm.com and it was a piece of cake to install.
Jeepman