I have a 1993 BMW E32 740i and my SRS light Blinks at start up then after a while it stays on?

ghead
I have been told that the Air Bag Sensor is bad? Where is it located in my car so I may change it out.
I have new air bags to put in it as well just in case, but I do not think it is this..
Is there a way to Diagnose this problem?
Thank you
Robert
Houston, Texas