If one is to believe the wiring diagram for the BAC-028X Motor Controller @
http://www.goldenmotor.com/ then the manual, at the same place, is wrong.
The diagram shows that you short the horn connection to activate the alarm; whereas the manual states that you must short the cruise control in order to activate the alarm.
In any case this may be the cause for many misunderstandings on how to use the alarm system, and GM should make the necessary corrections.
It seems a bit ridiculous that one should sound their horn for 10 seconds in order to set the alarm.
I have tried a switch in the position shown, from the small red wire of the V+ to G, and the only thing that occurs is the LED lights to the throttle switch on/off. The power remains on and holding the cruise button for 10 seconds does nothing.
This amounts to the alarm being useless until GM creates a fix.
There is a splice in the horn wire to H as though some one attempted that as a fix.
Evidently the vender sent me a used item. There is no label on the controller so I have to accept what is on the invoice; BAC-028X