Synthead

I have noticed that it is common to have a common postitive in a security system. This kinda makes me wonder ... Most cars have a common ground, so how does this work? Say, for example, I wanted to connect my door-open switches to the brain. If I connected the ground from the switch to the trigger, it would probably send the chassis to the brain and make it think that it's always open. But I'm not sure. What's going on?

VPUPPY

the common positive you refer to is just a regular power for the alarm brain. it runs all the logic chips and any built in relays. it also may use that same source to power the parking lights also.

the door locks work like this, if you have any honda they have (-) negative trigger locks, meaning if you put that wire comming out of the switch to ground, it will activate the door locks. there should be two wires that are negative trigger, the door lock open and the door lock close. the wires comming out of the alarm brain, the trigger wires, run to relays that are in the brain(some alarms have external relays). when you active the alarm to lock, it sends a pulse to the built in relay relay, which puts the trigger wire to ground as long as the relay is active. hope this helps cuz i had a hard time trying to understand what you are asking. visit the12volt.com, its a great resource.

Synthead

Thanks again for the great info! You're a real helpful member here. I really appreciate you taking the time to answer questions like this!

So basically, the negative trigger is just the positive lead coming in contact with the common ground? That makes it all so simple to understand! So if I were to wire up anything, I just need to find where that wire goes under the dash. Nice!

VPUPPY

no exactly. see, out of your door there is two wires that run into the car under the dash. they are running to your cars relay that works for your door locks. one wire is for the door lock open, and the other is lock close. now, when you activate the switch on your door, its actually giving one of the wires(either lock or unlock) that run under your dash a ground. that ground is, again, for a relay that will activate the door locks.

sometimes these wires(lock and unlock) don't leave the drivers door because sometimes the door locks are controlled by a module in the drivers door that also may work to control your windows. this is not on all cars, but many have this setup.

btw, thanks, i try to be helpful, sometimes i can but sometimes i can't. just another day as a HAN member...