I have been trying to troubleshoot my alarm in my 79 but still to no avail have i got it working. I have found my two sirens horns, whatever you wanna call them, one is in the front driverside gill and the other is up against the firewall. Whenever i open a door or close a door i can here the relay go "click" but not when i open or close the hood. It also clicks when i lock or unlock the driver side door from the outside. Is there anything else i am missing here? t-tops perhaps?

 

ttt

 

Ok i think i have narrowed(spel?) it down to the last part of the alarm (brains to siren) where is the wire that connects these 2? In the engine compartment the wire is orange but there are a lot of orange wires in the console area :banghead:

 

I can't help you much, but I am reading this with interest. :cheers:

I need to get mine working again too. keep us posted.

 

I believe that the 79 only has one horn and thats located on the inside of the drivers side fender somewhere under the master cylinder. Yes there is an orange wire that goes to this horn. most of the ones I have seen are disconected, just like mine....LT

 

Are you trying to troubleshoot it without a wiring diagram? Break out your Assembly manual and find the alarm circuits in the wiring diagram in order to determine what goes where. If you don't have an assembly manual, order one today. You'll wonder how you ever got by without ine in the past.

:cheers:

 

Ya i got my haynes manual and its got the schematics, but isnt much of a help on the alarm or well any electrical circuit for that matter.

 

I'm not trying to come down on you, but if you're really serious that the wiring diagram is not helpful then you ought not be working on the electricals of your car. It should be trivial to use the schematic to trace the wiring from the horn back to the source. Take out a spare sheet of paper and draw out the alarm circuits as you trace them through the wiring diagram. That way you will have an isolated diagram of just the area that you're working on.

 

Ok ive been testing the voltages in the circuit and have found that the voltage across the siren is always 12 volts(high), it never goes low. I then hooked up a siren from another alarm that i have and it wouldnt go off, it just kept sirening(i know its not a word). Could this mean that i have a bad relay or flasher? It cant be a connection problem because i am getting 12 volts at the orange wire to the siren. But i am thinking that something has shorted out in the brains of the alarm, which i assume is just the relay and a flasher right?

 

The horn has to be grounded. That was my problem. :yesnod: :seeya

 

Ok ill try to manually ground the horn then.

 

I know a bit about the 82 system so maybe this will help. The horns used are the regular pair of high/low pitched used for honking at people. The 12v+ is triggered by a common relay that can be activated from the horn button or the alarm system. When the alarm goes off they are cycled on and off very quickly for added nuisance factor. I believe it is a green wire from the horns to the relay which on mine is in the jungle above the fuse panel.

There are a pile of trigger switches that are all connected by a light blue wire. This includes doors, tops, door locks, and on yours the hood. They connect to ground when the door/top etc is opened. Check this circuit to make sure it is not grounded when everything is shut. There is a also a switch that monitors the key position in the door locks. These activate/deactivate the system and should be checked for operation. A second switch is on the door lock to monitor if someone breaks out the lock. It is tied into the common blue wire circuit.

Arm System:
1. Ignition off and one door open
2. Hit power locks or lock both manual locks
3. 10-15? seconds after door is closed alarm is armed

Disarm by unlocking a door. Or you can turn on the ignition which is tough to do with both doors locked (unless your still inside).

There is a starter interrupt relay which prevents the starter from turning if the system is all excited from a break in or you are in real hurry to go somewhere. :lol:

Dane

 

Nice discription Dane, I printed it out for when I get off my butt to work on it.
:thumbs:

 

Very nice indeed, maybe i am not waiting long enough to trigger the alarm so i will try again after skool tomorow, yes it is that time of year again :cry .

 

All that junk hanging on makes it very easy to put a aftermarket alarm in. Most of the wiring is done for you. I did it not so much for the extra alarm features but I absolutely LOVE the remote door lock/unlock. :thumbs:

Dawg, I'd be willing to bet your CE has a switch on the hatch too. I could never find one on the hood of my 82 but I know other years have them.

Batts - Too bad about skool but where else can you find 600 single women in one spot. :D

Dane

 

I just restored mine. Get the GM electical diagram (some post this alarm diagram on the web. It is fairly simple. The switches are wired in series. The switches are normally closed siwtches. If any switch opens the alarm will sound. the easiset way to diagnose is to work fromthe horn back. On my '78 there is one horn. It is mounted on the firewall just under the power booster. Open the door, enable the alarm and measure the voltage. If the circuit is working you should get a pulsing 12v at the horn. In my case I got a solid 8v at the horn. The culprit was a $1.49 flasher, which is mounted in the console on the right side just behind the ashtray. There is a relay under the console as well which is a great point for measuring the circuit.

 

yes i believe it is the flasher as i previously did what you described and i got a steady 11.87 volts.

 

hmm, $1.49 flasher eh, i just phoned the parts store and they said its a dealer item, the dealers want $9.25. I'm not paying 9.25 for freakin flasher, last time they got me with their $8.70 parking shoe spring but they aint getting me this time. Would you mind telling me where you got yours from?

 

battsup,

My apologies on the 82 version of alarm description. :( It has no resemblance to your 79 if the schematics I am reading are correct. The rest of this is based on my reading from the book so hopefully it is near right. Gliot1 is correct there is a single firewall mounted horn that squawks. The other is your regular horn and they are not interlinked.

You do not have a delay in arming the system it is turned on with the driver door key. A pretty good scan for the 80 (close?) is here: http://iotech.no/corvette/technical/...tics/index.htm

From what I see you have constant orange wire 12v+ to the horn. A yellow ground side wire is run from there to your flasher which oscillates the signal. Then it on a light blue wire into the alarm relay. I cannot tell for sure but the flasher looks like a regular two pole turn signal flasher. If not Zip has them for $4.00. You could wire around it if you don't want the gyrating noise. :)

You should be able to do some easy tests at the flasher. Ground the yellow wire to the frame. This should turn on the horn constant. Remove that and ground the light blue wire to the frame. You should get an oscillated sound from the horn.

One interesting note on the way your system is wired, once set off its going to scream until you give it the key or the battery drains.

Hope this helps. Dane

 

Ok Dane, ever since my last post ive been in my car and i found all the things your talking about(the horn by the firewall is connected to the 2 by the nose and the one by the driver side gill is for the alarm) I checked to see if the flasher was working by swapping it into the turn signal location and it does work, so that is not the problem. However i decided to check the voltages for the flasher(2 prong type) when the alarm is not armed the voltage is .4volts and when it is armed it is .0 and when it is supposed to be going off it is .14 . But here is the weird part, as soon as the flasher is connected and i try to get a reading i always get 0 volts. I cant see what the problem is, the horn is getting 12.57 volts, the relays hot wire is getting 12.57 volts but im getting these very low numbers at the flasher.