'77 Alarm Problem

[Wendell Allen]

When we got our car, it came without a door key. And like a dummy, I removed the drivers side lock to take it to the locksmith to have one made ($20 that way as opposed to $100 if they remove the door panel and cylinder assy). In retrospect I obviously should have removed the passengers side. The problem with removing the drivers side cylinder is that all the switch components are a huge PITA to put back together. And as a side note, the alarm horn was disconnected when we got the car.

Anyway, I'm now at the point where I want to put it all back together, and I'd like to make sure my horn is working properly. Can anyone tell me under what conditions exactly the horn is supposed to work? Should it work if the passengers door is opened while the alarm is activated? How about if a window if broken on the drivers side, the thief reaches in and unlocks the door from the inside and enters the car? And how about if someone takes a dent remover or screw driver to the lock cylinder? I've never broken into a car before, so I'm not really sure how this thing should work. And if anyone has a URL or something to an exploded view of the switch on the end of the cylinder, I'd appreciate that also.

Guess it's time to buy an operations manual!

Thanks,
W

[Jack H.]

Re: '77 Alarm Problem

From the '73-77 Corvette Operations Manual & Performance Verification Test Guide:

"Anti-Theft Alarm: A burglar alarm is standard on 1973-1977 Corvettes. See the lock and key information. Check that opening each door and the hood activates the alarm" .... "The switch remained in this position until 1977 VIN 423736 where it was integrated into the left door lock switch; it is activated by use of the oval headed key in all locations."

[Alan D.]

Re: '77 Alarm Problem

Wendell,
The alarm system on a 1977 can be very difficult to trouble shoot or repair. From what you have said the alarm is set by the oval key in the drivers door. If the drivers door is locked with the key the alarm is set. The alarm will sound an intermittent horn if the following occurs; the passenger door is opened or the hood is opened or the the drivers door is opened. The drivers door can be tested with the window down and the lock knob is moved to the unlocked position and then opening the door. The only way the alarm can be disarmed is to unlock the drivers door with the key. The horn can be tested by applying 12 volts dc to the terminals. Make sure that you apply the positive voltage to the positive terminal and the negative to the negative terminal. The horn should sound. Other items to be checked are the door switches, the hood switch, the switch that is attached to the drivers lock cylinder and the alarm flasher relay.
Good Luck,
Al Dieterle