72 Anti Theft Alarm Issues

[Bob P.]

I trying to get my anti theft alarm system to work and have ran into some problems. I have new door ajar witches installed on the car at the rear door jamb. The keyed switch has been clean and installed properly. The horn was test on a battery before it was installed and worked fine. I opened the relay and it appears to look fine. The original flasher I'm not sure about, but I have replaced it with a new one. The switch at the hood is original. The issue I'm getting is that I measure the voltage when the system is armed at the plug going into the relay and on one leg I get 12 volts. I then install the relay and measure the voltage at the plug going into the flasher and I get 12 volts on both terminals. Is this correct? I have actually got the system to work a couple of times with everything in place. The horm will blow for a period of time and then everything will shut off. Not sure how to go about solving the problem or how to further trouble shoot it. Any help would be appreciated.

[Edward J.]

Re: 72 Anti Theft Alarm Issues

Bob, I don't have a manuel in front of me, but that sounds correct, Because the system works on grounds from the switchs, Once a door is opened a ground path is created to flasher which in return should make the horn start blowing on and off.

At one of my first regional meets I was a OJ in the operations of the 70/72 cars and one of the cars we judged had repo switchs which did not want to operate correctly, He had to wiggle the pins to get them to work. They are a very poor design. I would look for some NOS ones.