Security light/VATS system. Please help $$$

Okay , so I have NOT done ANY research on the VATS system in over 20 years.... but is that tied in with the PCM? IF yes , is there a way to verify that it is recognized by the PCM? Just thought I'd add another line of thought. only thing I remember about that old system anymore , is the wire that used to break in the column and swapping resistors in the keys. Damn......good luck. Look for 'pushrod' to post a suggestion , I think he's seen just about everything (not sayin' he's old or nuttin'!!)