I have a factory alarm and it (sorta) works.

When I insert the key and turn it to turn it on, then pull it out, the alarm goes off. Um... Shouldnt it wait until I try to open the door or something?

 

Hmmm, sounds like something is amiss. I am no expert on these by any means. It may be working as intended .

The "alarms" that came installed are kinda cheesy IMO. Now that I think about, car alarms in general are not much of a deterent if someone wants your car.

 

Yeah, I know. I just wanted to see if it worked. And it does, just not the way I expected.

 

I think there are relay(s) in the storage bin area ... might
be corroded or stuck closed. A little tinkering around there
might free it up - or at least identify the problem.

So, just get a sticker made (for above the alarm lock) that says
"Unlock doors here" ... with the key in it.

 

Have You checked the alarm switch on the hood ? It may be closed
even with hood closed instead of open.

 

The key switch may be bad. I never set my alarm with the key though. I just hit the power locks before I get out of the car. I tested the alarm by leaving the window down and opening the car from the inside an it works. I think there are 5 alarm points on the car. T-tops both sides, both doors and the hood. You either have a bad alarm switch somewhere or a short that is activated with the key.

 

Where is the alarm switch in the hood?

 

Sounds like the Ttop switches are a 78-82 deal ... never saw any on early C3s.
Anyone have a picture of the Ttop switches ??
Hood switch should be between the wiper motor and blower motor,
mounted at the top of the firewall on an "L" shaped metal bracket.

Here's a pic ... right in the center of this picture is the L bracket with the two wires ... switch is out at the moment.
http://NHvette.com/ftp/in/alarm_switch_75.jpg

 

Mounted to firewall, kind'a toward the pass. side. When You
close hood it pushes spring loaded switch down for open circuit,
when You open hood circuit closes and if alarm is set,horn sounds.

 

OK, Im a little confused. I see it. Looks kind of like a nail, right?

What exactly should I be seeing if this is the problem?

 

Sounds like you have a short circut or a switch out of adjustment.

Funny this thread should come up I am right in the middle of working on mine. This is how I checked mine out. I connected a Volt Ohm meter to the circut wires where the underhood switch is located. I did not get any contunity untill I opened the door or with the window down tried to remove a "T" top. I did one at a time. That way I knew all the door and top switches were working. The hood switch was next. I made up two pig tails to connect to the switch. I made the leads long enough to run them out of the engine compartment. Again I used the volt ohm meter to check the switch. With the hood closed the circut should be open. Pop the hood and the switch should close. With all these switches checked out next was to check the arming switch. I pulled the wires off the Flasher relay located under the console and inserted a light. That way I could watch the light for the presesnce of power. I pulled the drivers door pannel the arming switch on my 79 is on the back side of the drivers door lock. With the key in the lock you turn it counter clockwise to lock the door and set the alarm. My switch is bad you can set it ok but when you remove the key it would turn the alarm back off.
[/QUOTE]
In the picture you can see the "T" top switches for 78-82 on the mounting plates. I don't think pre 78's had any.

Go here to see the Hood alarm switch http://www.zip-products.com/Zip/prod...2D03AEC9128034

Need more help drop me a note.

 

I have a 76. And unfortunately I have no idea what you just said in that post.

 

Do you have a multi meter?

 

No. I was going to buy one this weekend to check my alternator, but I realized it was a loose wire that was causing my problem and fixed it, so I didnt bother to buy one.

 

There a handy tool to have and they make checking out wireing problems much easier. On your car I believe that you will only have three switches that set off the alarm plus the key switch that arms the system. Do you have the key switch in the front fender?

 

Yeah, where the Stingray emblem is.

 

Yes try this, I had this problem with mine, remove switch and clean and adjust height so operates properly when hood closed.

 

Well, I can push it down with no problem. It pops back up when I release it...

 

I have a 75 and had the same problem. You should have switches on each door and one on the hood. The key switch in the fender has a backup switch that is mounted directly in contact with the back of the key switch. The purpose of this switch is if someone inserts a slide hammer into the opening of the key switch and rips it out then the backup will activate the alarm system. This switch is called the alarm switch. It looks almost identical to the headlight door opening switches that activate when the headlamps are in the up position. It is a small black plastic switch. Ecklers has it on page 46 of their C3 spring summer catalog. Part #42127. Yours may just need to be adjusted so that the switch is contacting the key switch. Send me your e-mail address and I can send you a pic from the assembly manual.
Good Luck
Steve

 

The above is most likely your problem...I had the same experience on my '77. Try reaching down in the engine bay along the fender and "adjust" the connection on back on the key switch...If you do it with the alarm in the on position and something holding the hooding switch down you will know if it is the problem...I adjust mine once or twice a year...