Alarm Anti-Theft?

[CAPNZ]

Anyone know what the major cause of the Anti-Theft system not working on a 73? The switch/contacts look good. I know how to check things out but I would like a starting point. A few more things and my 38k mi. 73/454 will be 100% working and loooooooooookin' gooooooooood!
TIA
"Jeff"

 

[en2burrell]

Jeff:

Did you first check if someone had pulled the fuse? If the fuse is in place, is it intact and completely free of corrosion? Are you sure? You may want to install a known good fuse to be sure. Also make sure the fuse holder is free of rust or corrosion.

When you say "the switch/contacts look good", I must assume you verified electrical continuity through the main switch and that the electrical connections (including the grounds) were disassembled and were verified to be completely free of rust or corrosion. You may also want to check the anti-theft relay and flasher (both located in the tool compartment), the wiring harness and the horn itself. A good wiring diagram and the factory assembly manual would be helpful.

-en2burrell

 

[emf1367]

Jeff,

After confirming the fuse is good then I suggest you check to make sure you have power just before and after the switch. Once this is done you have eliminated two main things. Now check to make sure the horn functions. Once you confirm it is working you can also substitute a test light for the horn. I always do this so I dont have the horn blaring each time it gets power. Works well if you have little ones sleeping during the day.

Once you've confirmed these three things are functioning then it's time to check all the contacts (doors and hood). Of course do all of this after you've followed en2burrell's instructions/advice.

The system isn't as complicated as you might think. If you have power to the relay and the key switch and the horn functions but it still wont work then you have an open circuit (break in the wire or faulty contact/switch in the doors or hood). The wires for the door contacts are located behind the seats. They run from door jamb to door jamb (horizontal) on the vertical section behind the seats, a few inches below the shelf. I've seen the wires crushed from the seats or stuff being stored behind the seats. I've also seen them pulled loose from the contacts within the door jamb.

Good luck!

 

[USNA1969]

It just so happens that I fixed the alarm on my 72 this morning. I found that the contacts did not extend all the way through the plastic contact holder on the end of the plunger. In addition, when I pushed them through, they were so dirty that they needed to be sanded a bit. I also put a small amount of grease on the plungers because I found that they extended slowly, and I figured that if they are slow today, they'll be stuck tomorrow. Hope this helps. Good luck.

 

[mkapp7879]

I had an alarm horn go bad. I would trigger the alarm and I could hear the relay clicking. Checked the horn, dead.
Mike

 

[CAPNZ]

Thanks Guys!
These are the tips I need. Will keep you posted.
"Jeff"

 

[CAPNZ]

Got er werkin'. Albeit,the switch is stubborn. I sprayed some carb cleaner & WD down the key slot and it helped. Does anyone know how to get the key tumbler out? If I buy a new switch I'll need my original key to work for judging standards.
TIA
"Jeff"

 

[Maymyvetteliveforevr]

Click on the link below, and the most help is in the last post.

http://www.corvettefaq.com/redir.asp?site=407

Good Luck

Frank

 

[CAPNZ]

Thanks Frank, GREAT LINK! But I'm looking how to get the tumbler OUT of the switch. It's all sealed around the edge. Just like getting the key tumbler out of a door lock.
TIA
"Jeff"