I thought there was a relay diagram somewhere on this site about how to do it, but I can't seem to find it.
Anyway, to begin with, you'll need to add a motor in the driver's door, and control it with a pair of relays---this part is explained in the Relays part of the website we're on now.
Next comes the challenging part. I've never attempted this before, but I think I have an idea how to do it.
Next, let's look at what you have available coming from your alarm. You're saying there's a wire that goes to the proximity sensor---it's testing as positive when armed, and ground while disarmed.
Well, I'd go ahead and make one more test---cut that wire in half (or unplug) the proximity sensor, and test again. The wire that comes from the alarm most likely only has one function-----it's either positive while armed, or negative while disarmed-----but it's very unlikely to do both functions. It most likely only shows one of these functions because an electrical load (the proximity sensor) is attached to it---disconnecting the sensor will give you a more honest answer.
Anyway, whichever way that wire happens to be, it might change some of the ways you'll wire things up, but only in a very minor way.... we'll get to that in a moment.
Next, your alarm has a connection to the lights, you said. And I'd imagine that the lights flash when you arm and disarm the alarm, right? Well, we'll make use of that too.
All you have to figure out is this: When the alarm is armed, the parking light flasher will also lock the doors....when it is disarmed, it will unlock the doors. And you have that other wire going to the proximity sensor that will indicate whether the alarm is armed or disarmed, right?
So, you'll want to make a relay setup that is triggerd by that wire going to the sensor......the wire will control the relay, which will be used to direct the light flash output to lock, or unlock, the doors.
Now, there are a few things to think about here:
-You can't have the relay stay in the "on" state the whole time the car is armed---this would drain the battery if parked for long periods.
-You'll need to use diodes to isolate your car's lights from the system you're about to make---you don't want the locks to move back and forth when you turn your lights on for nighttime driving.
-Your alarm system probably flashes the lights a certain number of times, depending on what's happening----probably one flash for arm, and two for disarm. So when you go to disarm, it's actually going to unlock your doors twice, causing a little extra wear....sorry, there's not much that can be done about that.
-When a thief breaks into your car, the lights also flash, correct? Because of this, the alarm will keep re-locking the doors over and over during a break-in...this is actually probably a good thing.
So, if you don't already know how relays work, spend some time reading through the sections about them. I can try to help you all I can, but since I've never done this before, I can't guarantee you that everything will work as described....but it would be fun to find out!
Topic Closed)
Members
Search
Register
Login
Printable version
