By - Vince Galti (VinVin)
This tutorial was written to give you, the installer, an understanding of how to go about the installation of your own alarm. Because each car is different, some of the things in this tutorial will not apply. If this is the case, seek Professional Help.
The Alarm that we will be looking at in this tutorial is a simple remote controlled alarm usually sold in the price range of $300 to $400.
It is a Dominator DM-785 Alarm.
Its "main" features include Engine Immobiliser, Remote controls, Shock Sensor (built in), LED status light, Flashing display (indicators), with many optional extras..
The typical wiring diagram for this alarm looks like this:
Though, at first this kind of diagram seems complicated, its actually quite simple. Understand an alarm as "a device, which is adapted to your car which serves the purpose of screaming."
Therefore, all the wiring diagram is showing you, is how to hook up each separate feature into your car. As mentioned before, Each car is different, some very different, but all share a common method of installation. This is why I have chosen not to document the actual installation of an alarm to a random model car. A 12v test light will make you job a lot easier. Also, solder all connections and tape well.
The first step is to remove any wires which do not apply to you. To do this neatly, remove the alarm module from the box, and plug all the wires into it. Now screw the alarm to your bench with the wires hanging down in front of you. Now you can play with the wires. Keep in mind the best place to mount the alarm un under the drivers side of the dash, between the steering column and the drivers door. Inside the dash so that it cannot be seen.
Looking at the diagram, and starting from the top:
BLACK: Ground wire. Does not have to run to the battery, just to a screw or bolt in the vicinity of where you mount your alarm.
RED: Power 12v+. This does not have to go to your battery. You will find 12v+ in the main lume which runs to the key barrel.
BROWN: + Siren output. Keep in mind that it says "+" and "output" which means that the alarm is sending OUT on that wire a + signal. This goes to your siren. This is the wire that gives the siren the 12v which sets it off.
WHITE: + Parking lights. Again, "+" signal going out on this wire, to go to the indicator control wires in your car. These wires are found in the lume that travels to the indicator level near the steering wheel.
ORANGE: - Starter Killer. This wire triggers the Immobiliser Relay.
BLUE: - Trigger. This wire is where you input a negative signal to set off your alarm. Off this wire you run a wire to the boot and to under the bonnet to pin-switches you have to install.
GREEN: - Door Trigger. This wire is connected to the pin switches in your door ways to trigger the alarm if someone opens the door.
VIOLET: + Door trigger. This is for cars which have + triggered wires connected to their doors instead of negative triggers.
YELLOW: Ignition 12v+. This wire it to be connected to the ignition wire, also found in the main lume running to the key barrel of the steering column.
RED/WHITE: - Trunk Release. This wire is connected to your electronic truck release button, if applicable to your car.. This is so you can pop open your boot via remote.
Now that we have a brief understand of our car, we’ll go through the grouping of the wires, for making a nice, tidy installation.
Looking at you alarm, conveniently screwed to your bench, we can see all the wires. What we want to do, is to group the wires according to the location they have to go.
Get the following wires and lume them up together with tape, creating a neat black insulated stream of wires.
Get some black wire, and splice a second black wire onto the alarm black wire, up near the module, so now you have 2 ground wires.. Do the same with the Blue wire, so that we have one wire to run to the bonnet and one to the boot.
RED, WHITE, ORANGE, YELLOW. These wires will all be found under the steering column in the few lumes that run up to the ignition barrel and to the indicator levels. This lume you have created will run to the steering column.
BLACK, BROWN, BLUE. Obviously only on of the black wires and one of the blue wires, then the brown wire as well. This lume will run through the firewall of the car to the engine bay.
BLACK, stays free as it will go where it has to to find a good ground.
BLUE, run this wire into your boot.
GREEN, Leave this wire free, as it may go to a few places.
VIOLET, Cut this wire off, its not needed because the this car is going to have negative triggered doors. Obviously if it had positive triggered doors, then the violet would be left, and the Green would be cut off.
RED/WHITE, cut off as well, no trunk release on this car. If it did, you would run it to the button and hope that the car boot is triggered by a negative signal.. If not, you will need to hook up a relay, to convert the negative signal from the alarm red/white wire into a +’ve signal to activate the boot release solenoid.
This tutorial will not go into hooking up central locking to the alarm. It would be nearly impossibly to describe a common situation.
- Unscrew the module from the bench and get comfortable on the floor next to the drivers door.
- Unscrew the plastic panels under the dash and the ones concealing the steering column. What you see in front of you now, is all you really need.
- Find a good location to stick/mount the alarm module and do so.
- Now run the lumes we have prepared to the designated locations where the necessary wires will be found.
- Starting with the black wire, find a suitable bolt/screw into metal that will act as a good earth for your alarm.
- Now, un-peal the protective plastic off the main lume which runs up to the back of the ignition barrel.. you should find lots of thick wires. This is where you will find 12v+ and Ignition.
- Now, also one of these wires will be the starter motor wire. This is the wire which receives power exactly as the starter motor cranks over when starting the car. Cut this wire in half. You will find that you cannot start your car now, hence "immobilized".
- In the box you will find a relay and a plug for it with 4 wires coming off it. In this case its 2 thick red wires, a yellow wire and an orange wire. Connect one of the red wires to one half of the wire you just cut, and the other red wire to the other half. Now, connect the yellow wire to the yellow wire coming from the alarm, and the orange wire to the orange wire coming from the alarm. Tape up the relay and the relay lume and wire-tie it neatly out of the way. Immobiliser is done.
- Find the lume which runs to the level to activate your indicators. Turn you key to Ignition position and turn on the left indicator. Using a test light, probe the wires in this lume till you find the wire which flashes the test-light with the indicators. Once you found it, move the level to the right indicator and see if it still works. What we are looking for, is the wire which controls the LEFT ONLY and the wire which controls the RIGHT ONLY… not both. Inside the box, you will find a small "diode splitter". This is a wire which is joined to 2 diodes, creating a Y junction, then going off in two different directions. Join the foot of the Y junction to the white wire coming from the alarm, and then one white wire to the left and one to the right indicator control wires.
- Now, remove the plastic trim that goes from the dash, up the pillar to the roof lining.. Are there any wires behind this? If so, these are the wires which control your interior light, hence, are controlled by every door on the car. Find the wire that acts as a ground when the doors are opened, and connect the Green wire to it. If there are no wires here, connect the green wire to the wire attached to the back of the pin switch (rubber push button thingy) in the door jams which make the interior light go on and off.
- In the boot, you will find an interior light, it is controlled by the opening and closing of the boot. Pop out the light, and access the lume which feeds it. Using the testlight, find which wire is negative when the boot is opened. Connect the blue wire to this.
- Under the bonnet, screw the sire down in a neat, safe place, facing down. Now off the siren there is a red and black wire. Connect the black wire to the black wire coming from the alarm, and the red wire to the brown wire coming from the alarm. Hence, the siren has always got a ground, but awaits the 12v+ from the alarm to go off.
- In the box you will find a Pin-switch.. Drill a hole in the cross member at the front of the car, and mount the pin switch there, connecting the blue wire to the bottom of it. Adjust the height so that the bonnet pushes on the pin switch when closed.
- Find a neat spot in the dash and drill an appropriate hole to mount the LED light. Run it to the alarm module and plug it in.
This alarm would be a fitters dream, as it was pretty basic. Most cars are like this. In doing alarms, you gain an understanding on how they work and therefore you find ways to figure out the complexities in the more difficult of cars.
If you look under the dash, providing you have taped everything up neatly, hidden the module well and restored everything to its factory position, then it should look as though you haven’t even touched anything. This is the sign of a neat install.
Good Luck with your install.