Anti-theft system problem

[Kurt G.]

I finally got the alarm system on my '72 semi-working, but have a problem. When the system is armed and the hood is released, the horn sounds fine. However, when either door is opened the horn is silent and the door ajar light on the instrument cluster flashes. Any suggestions anybody?

[Edward J.]

Re: Anti-theft system problem

Kurt, I'll take a look at the operation of my 72 and see if this is normal, I have never tryed this with my 72 ,does the alarm work normal with the doors opened one at a time or with both doors open?

[Harmon C.]

Re: Anti-theft system problem

The alarm horn is sometimes very hard to get working correct. The archives has lots of posts you could read that may help. The door adjar light flashing could be a ground problem. The horn seems to be the problem even when it will work with the hood as this has happened to me. I had good results buying a new cheap horn of any type to test the system to get it working. Alarm horns that test good on a battery may not work when installed has been the case for me many times.

[Edward J.]

Re: Anti-theft system problem

Kurt, I did check the operation of my 72 and the horn will sound with the door and hood open at the same time.

The doors and hood switchs only proved ground pathes to the the relay. when the black and white wires are grounded through each switch, so my guess is one of the door switchs is not grounding to the relay properly, and and instead your door ajar ground,and is causing a the light to flash because they work on the same switches.