How does the alarm system work on a 76? - CorvetteForum - Chevrolet Corvette Forum Discussion

Register FAQ Search Today's Posts Mark Forums Read Vendor Directory

C3 General
General C3 Corvette Discussion not covered in Tech Sponsored by
Corvette America

How does the alarm system work on a 76?

Reply
 
 
 
Thread Tools Search this Thread
Old 07-14-2006, 09:53 AM   #1
Vette Gator
CF Senior Member
Thread Starter
 
Vette Gator's Avatar
 
Member Since: Dec 2004
Location: Gainesville FL
Posts: 919
Thanks: 0
Thanked 2 Times in 2 Posts
Default How does the alarm system work on a 76?

My car came without either of the two fender switches (both the keyed one you see from the outside and the one bolted next to it), but the rear horn is in place. I'm in the process of installing the missing parts using the assembly manual, but wanted to know how it's supposed to function when it's complete. When you turn the key and the hood and doors are closed, should there by any sound to let you know that the system is armed? If a door or the hood is opened, should the horn go off continuously or does it eventually shut itself off? Without ever having seen one working correctly, I'm shooting in the dark as a I put it back together and troubleshoot.
Vette Gator is offline   Reply With Quote
Old 07-14-2006, 10:03 AM   #2
...Roger...
CF Senior Member
 
...Roger...'s Avatar
 
Member Since: May 2006
Location: Dayton, Ohio
Posts: 16,529
Thanks: 0
Thanked 5 Times in 4 Posts
Default

Quote:
Originally Posted by Vette Gator
My car came without either of the two fender switches (both the keyed one you see from the outside and the one bolted next to it), but the rear horn is in place. I'm in the process of installing the missing parts using the assembly manual, but wanted to know how it's supposed to function when it's complete. When you turn the key and the hood and doors are closed, should there by any sound to let you know that the system is armed? If a door or the hood is opened, should the horn go off continuously or does it eventually shut itself off? Without ever having seen one working correctly, I'm shooting in the dark as a I put it back together and troubleshoot.
There is no arming sound.I dont think it will shut off until it is turned off.Its just a relay and a flasher.
...Roger... is offline   Reply With Quote
Old 07-14-2006, 12:10 PM   #3
BenUK
CF Senior Member
 
BenUK's Avatar
 
Member Since: May 2005
Location: South of London, Engerland
Posts: 1,146
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by Vette Gator
My car came without either of the two fender switches (both the keyed one you see from the outside and the one bolted next to it), but the rear horn is in place.
I have a '76 and I'd love to know more about the alarm too. My car has the body keyswitch and the horn but I've never seen a second fender switch. Could you give more info please? Do you have any photos or diagrams I could see?

Thanks for any info you can provide. My alarm's never worked, but maybe only because I've never tried. I don't have a key for the fender lock.
BenUK is offline   Reply With Quote
Old 07-14-2006, 12:24 PM   #4
classiczx
CF Senior Member
 
Member Since: Oct 2005
Location: Old Skool, NY
Posts: 1,501
Thanks: 0
Thanked 0 Times in 0 Posts
Default

My original alarm is supposed to work but disconnected for shipping i'm told. But i'm worried about a 30 year old alarm system malfunctioning and locking up the car to have someone check it out & reconnecting the wires... or something like that.
classiczx is offline   Reply With Quote
Old 07-14-2006, 01:30 PM   #5
Greg
CF Senior Member
 
Greg's Avatar
 
Member Since: Feb 1999
Location: Palm Springs....but it's a "dry" heat, CALIFORNIA
Posts: 2,555
Thanks: 0
Thanked 0 Times in 0 Posts
Default

If your alarm malfunctions it won't lock up the car.

It works on the same principle as your interior lights. When the system is armed and the hood or door is opened the horn is energized. It is interupted by a simple signal flasher so the horns sounds on and off until it is reset with the key.

This basic system is usually pretty easy to get working. Install new door switches, flasher and horn, if needed, and you've covered the whole system.
Greg
Greg is offline   Reply With Quote
Old 07-14-2006, 01:37 PM   #6
gq82
CF Senior Member
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
 
gq82's Avatar
 
Member Since: Sep 1999
Location: AnyTown NJ
Posts: 4,930
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by Greg
If your alarm malfunctions it won't lock up the car.

It works on the same principle as your interior lights. When the system is armed and the hood or door is opened the horn is energized. It is interupted by a simple signal flasher so the horns sounds on and off until it is reset with the key.

This basic system is usually pretty easy to get working. Install new door switches, flasher and horn, if needed, and you've covered the whole system.
Greg


Pretty simple system....I don't know if it's the same horn but the one on my 71 sounds like a dieing goose.
gq82 is offline   Reply With Quote
Old 07-14-2006, 01:46 PM   #7
classiczx
CF Senior Member
 
Member Since: Oct 2005
Location: Old Skool, NY
Posts: 1,501
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Thanx for the info!

...so it's just all flash and noise then... guess i'll let an alarm tech have a looksee and maybe add another alarm with additional features to go along with it.
classiczx is offline   Reply With Quote
Old 07-14-2006, 04:11 PM   #8
Vette Gator
CF Senior Member
Thread Starter
 
Vette Gator's Avatar
 
Member Since: Dec 2004
Location: Gainesville FL
Posts: 919
Thanks: 0
Thanked 2 Times in 2 Posts
Default

The other switch is inside the car, and it appears that an arm on the keyed switch must hit it when the alarm is turned on. It looks like the switches on the headlight mechanisms that trigger the headlight warning light on the dash (not sure if they're identical or not, but they look similar). I have the picture in my assembly manual, but since I'm at work, I can't give the page number (it's near the back). Interestingly, I checked out a friend's 75 last night, and that year only had the key switch. The worst part is going to be getting access to this area. I can't imagine why a former owner would have removed the switches. It looks like a lot of work!
Vette Gator is offline   Reply With Quote
Old 07-14-2006, 04:24 PM   #9
BenUK
CF Senior Member
 
BenUK's Avatar
 
Member Since: May 2005
Location: South of London, Engerland
Posts: 1,146
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by Vette Gator
The worst part is going to be getting access to this area. I can't imagine why a former owner would have removed the switches. It looks like a lot of work!
Thanks for the info.

Before my recent repaint I removed the lock switch from the body and it wasn't too difficult to access that area once I'd removed the washer fluid bottle from that fender. You have to work at arm's length with a big pair of pliers but it's all pretty accessible.

Incidentally I'm pretty sure there's no additional microswitch on my fender. There are no external mechanical components to the lock switch on my car - just two electrical connections (red and purple, I think) so there are no moving parts to activate another switch.

My car was built in May '76 - maybe later ones had a more sophisticated system?
BenUK is offline   Reply With Quote
Old 07-14-2006, 05:28 PM   #10
Mark PittPayne
CF Senior Member
 
Mark PittPayne's Avatar
 
Member Since: Sep 2005
Location: Hamilton Ontario
Posts: 194
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I wish you luck. If you can get the alarm to function properly then you should get a job at GM. The systems were junk. They worked alright....all the time whether the door was opened or not. I'm not sure on this but I think there was a thread where removing the Ttops would also set it off and that was a major cause for original alarm failures. As I said not 100% on that one.

Gitter done.
Mark PittPayne is offline   Reply With Quote
Old 07-14-2006, 05:30 PM   #11
...Roger...
CF Senior Member
 
...Roger...'s Avatar
 
Member Since: May 2006
Location: Dayton, Ohio
Posts: 16,529
Thanks: 0
Thanked 5 Times in 4 Posts
Default

Quote:
Originally Posted by Vette Gator
The other switch is inside the car, and it appears that an arm on the keyed switch must hit it when the alarm is turned on. It looks like the switches on the headlight mechanisms that trigger the headlight warning light on the dash (not sure if they're identical or not, but they look similar). I have the picture in my assembly manual, but since I'm at work, I can't give the page number (it's near the back). Interestingly, I checked out a friend's 75 last night, and that year only had the key switch. The worst part is going to be getting access to this area. I can't imagine why a former owner would have removed the switches. It looks like a lot of work!
Gator that switch inside the body is a tamper switch
...Roger... is offline   Reply With Quote
Old 07-14-2006, 05:34 PM   #12
...Roger...
CF Senior Member
 
...Roger...'s Avatar
 
Member Since: May 2006
Location: Dayton, Ohio
Posts: 16,529
Thanks: 0
Thanked 5 Times in 4 Posts
Default

QUOTE-I'm not sure on this but I think there was a thread where removing the Ttops would also set it off and that was a major cause for original alarm failures. As I said not 100% on that one.

Gitter done.[/QUOTE]------------------Mark------I think that started in 78--when the T-top release went to a single handle

Last edited by ...Roger...; 07-14-2006 at 05:37 PM.
...Roger... is offline   Reply With Quote
Old 07-14-2006, 06:16 PM   #13
classiczx
CF Senior Member
 
Member Since: Oct 2005
Location: Old Skool, NY
Posts: 1,501
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Its probably not practical to actually have the original alarm activated on a daily basis... but it'll be cool just to have it working.
classiczx is offline   Reply With Quote
Old 07-14-2006, 06:33 PM   #14
MartyW
CF Senior Member
Support Corvetteforum!
 
MartyW's Avatar
 
Member Since: Nov 2005
Location: Breckenridge Colorado
Posts: 832
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by dwncchs
------------------Mark------I think that started in 78--when the T-top release went to a single handle
The T-Tops on my 76 only have a single release handle. You think my previous owner gots tops off another year? My vin says it was made in January of 76.

Last edited by MartyW; 07-14-2006 at 06:38 PM.
MartyW is offline   Reply With Quote
Old 07-14-2006, 06:49 PM   #15
Vette Gator
CF Senior Member
Thread Starter
 
Vette Gator's Avatar
 
Member Since: Dec 2004
Location: Gainesville FL
Posts: 919
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by dwncchs
Gator that switch inside the body is a tamper switch
Aha! Now the assembly manual instructions make perfect sense. I couldn't understand why they said to make sure that the button on the inside was up against the keyed switch. I thought it meant that should be in contact when an arm was moved. Now I see that it means with the barrel of the keyed switch to set the alarm off if someone tried to remove it. That's pretty clever!
Vette Gator is offline   Reply With Quote
Old 07-14-2006, 07:10 PM   #16
BenUK
CF Senior Member
 
BenUK's Avatar
 
Member Since: May 2005
Location: South of London, Engerland
Posts: 1,146
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by MartyW
The T-Tops on my 76 only have a single release handle. You think my previous owner gots tops off another year? My vin says it was made in January of 76.

Definitely 2 release handles on the T-tops in '76.
BenUK is offline   Reply With Quote
Old 07-14-2006, 07:27 PM   #17
MartyW
CF Senior Member
Support Corvetteforum!
 
MartyW's Avatar
 
Member Since: Nov 2005
Location: Breckenridge Colorado
Posts: 832
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by BenUK

Definitely 2 release handles on the T-tops in '76.
I wonder what year they are from. The more I inspect the car the more wierd things I find. When I went to recover the seats last week I found out that I have 1st Generation 68 seats instead of my correct 76 seats so I had to recover with 68 seat covers and backs. Now it seems that I got later year T-Tops. Oh well, I guess the car is a Frankenstein car. At least it looks ok
MartyW is offline   Reply With Quote
Old 07-21-2006, 03:48 PM   #18
Vette Gator
CF Senior Member
Thread Starter
 
Vette Gator's Avatar
 
Member Since: Dec 2004
Location: Gainesville FL
Posts: 919
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Which way should the key slot face when the alarm is turned off - straight up or side-ways? I am trying to figure out which orientation before I clip the new key switch into my fender.
Vette Gator is offline   Reply With Quote
Old 07-21-2006, 04:19 PM   #19
BenUK
CF Senior Member
 
BenUK's Avatar
 
Member Since: May 2005
Location: South of London, Engerland
Posts: 1,146
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by Vette Gator
Which way should the key slot face when the alarm is turned off - straight up or side-ways? I am trying to figure out which orientation before I clip the new key switch into my fender.
The hole in my fender is shaped in a way that means the switch only fits one way, but I'm sorry, I can't remember which it is.

Edit: I think the clip at the back of the switch slides horizontally to hold the switch though, and that only fits one way. Maybe that helps.
BenUK is offline   Reply With Quote
Old 07-21-2006, 10:51 PM   #20
KenSny
CF Senior Member
 
KenSny's Avatar
 
Member Since: Apr 2001
Location: Olmsted Falls Ohio
Posts: 2,316
Thanks: 0
Thanked 1 Time in 1 Post
Default

76 is the same as a 75. I wrote a procedure to troubleshoot and repair the complete factory alarm system. I posted it here a few years ago. If anyone wants a copy of it just email me.
KenSny is offline   Reply With Quote
Go Back   CorvetteForum - Chevrolet Corvette Forum Discussion >
Reload this Page
  • How does the alarm system work on a 76?
  •  
     
    Reply

    Related Topics
    Thread Thread Starter Forum Replies Last Post
    75 Alarm problem gsimon767 C3 Tech/Performance 11 10-25-2016 11:44 PM
    78 Corvette Alarm lasmith03 C3 Tech/Performance 12 11-19-2013 03:11 AM
    My Horn Honks Without Pressing The Horn Button! Poodle Shark C3 General 8 11-17-2006 01:33 AM
    Factory Security System... I'm at the end of my rope!! Justardnck C4 Tech/Performance 22 11-27-2004 10:32 PM
    Factory security system.... I'm at the end of my rope!!! Justardnck C4 General Discussion 14 11-25-2004 12:11 PM


    Tags
    1971, 1976, 76, alarm, c3, corvette, factory, fender, interior, key, lights, pictures, sounds, system, work

    Thread Tools Search this Thread
    Search this Thread:

    Click for Advanced Search

    Posting Rules
    You may not post new threads
    You may not post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are Off
    Pingbacks are Off
    Refbacks are Off

    Forum Jump


    All times are GMT -4. The time now is 01:43 PM.