How does the alarm system work on a 76?
#1
Burning Brakes
Thread Starter
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.
#2
Race Director
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.
#3
Burning Brakes
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.
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.
#4
Drifting
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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.
#5
Just another Corvette guy
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
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
#6
Safety Car
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
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
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.
#7
Drifting
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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.
...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.
#8
Burning Brakes
Thread Starter
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!
#9
Burning Brakes
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!
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?
#10
Instructor
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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.
Gitter done.
#11
Race Director
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!
#12
Race Director
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
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 04:37 PM.
#14
Burning Brakes
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Originally Posted by dwncchs
------------------Mark------I think that started in 78--when the T-top release went to a single handle
Last edited by MartyW; 07-14-2006 at 05:38 PM.
#15
Burning Brakes
Thread Starter
Originally Posted by dwncchs
Gator that switch inside the body is a tamper switch
#16
Burning Brakes
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.
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bluthundr (08-29-2022)
#17
Burning Brakes
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Originally Posted by BenUK
Definitely 2 release handles on the T-tops in '76.
#18
Burning Brakes
Thread Starter
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.
#19
Burning Brakes
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.
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.
#20
Melting Slicks
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.