Steal Stopping - Part Three

In the first part of this series we devised a way to secure our Nissan 180SX for a total cost of under AUD$250. For Part Two we put together a tricky stand-alone immobiliser. Now, in the final two instalments, we’ll take you through the Do-It-Yourself installation of an off-the-shelf remote control alarm/immobiliser.

The Full Feature Steel Mate Car Alarm

The security system we installed in our 180SX is the Full Feature Steel Mate Car Alarm sold by Jaycar Electronics and the AutoSpeed Shop (Cat. No. LA-9005).

Retailing for AUD$149, the Steel Mate product features rolling-code remote controls, shock sensing, automatic self-arming, a battery back-up siren, immobiliser and a flashing LED. It can also be configured to operate central locking via the remote controls – one of the important features we were chasing.

This is what you receive in the kit. A compact alarm module, battery back-up siren with adjustable mounting bracket, two four-button remote controls, plug-in wiring loom with the necessary fuses, plug-in shock sensor, immobiliser relay, a pair of cable-ties and complete Do-It-Yourself installation/user manuals.

Note that the Steel Mate Alarm uses colour-coded wiring which, compared to the all-black wiring of some other brands, makes it easier for a thief to circumvent the system. On the other hand, the colour-coded wiring enables easier Do-It-Yourself installation – as you’ll see...

Do-It-Yourself Security System Installation

Mounting the Alarm Module

The first step is to find an out-of-the-way place to mount the alarm module. The Steel Mate module is quite compact and can be mounted high under the dashboard where it’s difficult for a thief to access.

In our 180SX we decided to remove the glovebox and mount the module under the far left side of the dashboard. The spot we chose cannot be affected by potential water leaks and does not get in the way of any other electronic equipment.

Note that we’d already connected the wiring loom to the module by the time we mounted it – accessing the sockets can be difficult once the module is secured.

The Steel Mate alarm module has a pair of elongated mounting tabs that can be used to screw it in place. However, for our installation, we used several strips of heavy-duty double-sided tape to secure the module. A flat, clean mounting surface was chosen to ensure maximum adhesion.

After the alarm module is mounted, it's time to start looking at where all those wires go...

Lengthening the Wires Note that because we decided to mount the alarm module on the passenger side of the vehicle, the supplied wiring loom was not long enough to reach many of the wiring connections. This meant we had to lengthen each wire to suit which, of course, is a bit of a pain. Retrospectively, we recommend mounting the alarm module under the driver’s side of the dashboard – this makes installation easier.

Test Run Wiring

The installation manual suggests temporarily wiring the alarm module to its base inputs for a test run; the final wiring connections can be made after the system’s basic performance checks out.

Note that, at this stage, the wiring doesn’t need to be tidily routed through the car – all we’re performing is a test.

Connect the module’s indicator output wires (brown) to the vehicle’s left and right indicator circuits. Note that the alarm has its own flasher circuit and output fuses so the connection can be made directly to the indicators. However, in this instance, we had access to a factory wiring diagram so we could easily identify the vehicle’s indicator wires beneath the dash - this approach keeps things a bit neater.

Next, connect the module’s brake pedal input wire (orange) to the vehicle’s foot brake switch. This is easiest to connect near the head of the brake pedal.

The alarm’s door position input (blue wire) must then be connected to the vehicle’s door-triggered courtesy lighting. The easiest way to do this is to remove the central dome light and probe the attached wires. The suitable wire for connection is one that shows 12V when the door is shut and approximately 0V when the door is open.

Now connect the alarm module’s switched 12V wire (white) to accessories. If you don’t have a wiring diagram, the vehicle’s accessories wire can be identified using a multi-meter. Twelve volts should show when you’ve turned the key to the ACC position.

The final wiring connections for the preliminary test are to earth and permanent 12V. The module’s earth wire (black) connects to the negative pole of the vehicle battery and the 12V supply wire (red) connects to the positive pole. You’ll need to buy a couple of crimp-type eye terminals to make a secure connection to the battery - none are supplied.

Note that the Steel Mate alarm’s permanent 12V wire is equipped with a 15A fuse near the module. We decided to fit an additional 15A fuse close to the battery for greater protection.

Now it’s time for the trial run.

If everything is performing correctly, the LED indicator should flash slowly when the system is armed via the remote control. Open a door (with the system still activated) and the LED should start flashing rapidly. Disarm the system via the remote and the LED should stop flashing.

Satisfying this, it’s time to tidy and solder together the temporarily routed wires.

In the case of our 180SX, we routed the permanent 12V and earth wires parallel with an existing wiring loom that passes through the firewall and travels forward in the cavity between the wheel arch and plastic guard liner.

If you can’t find a wiring path from the cabin to the battery you may need to drill a hole through the firewall. If this is necessary, make sure the hole is later fitted with a rubber grommet to protect the wires.

With the basic elements of the alarm neatly integrated we can now move on to fitting the add-on hardware – the siren, shock sensor and immobiliser relay.

Mounting the Siren

The Steel Mate battery-back up siren is supplied with a mounting bracket that allows the siren to be set at various different angles. The siren should be mounted in the engine bay somewhere isolated from rain and excess heat. Ideally, the siren should also be mounted where it’s difficult for a thief to locate.

Note that, in the case of our 180SX, we were forced to bend an L-shaped bracket from a piece of scrap aluminium to achieve our desired mounting angle – we couldn’t achieve the mounting angle we wanted using only the supplied bracket.

Using our fabricated L-shape bracket we mounted the alarm siren behind the vehicle’s passenger-side front strut tower - as far away from the turbocharger as possible.

Now it’s time to connect the wires attached to the siren

The siren should be earthed using its black wire and fed constant 12V using its red wire. The siren trigger wire (white) must be connected to the siren wire (pink) from the alarm module.

Note that you’ll need to purchase some extension wire to connect the siren to the vehicle’s battery terminals. These wires should be routed parallel with the vehicle’s existing under-bonnet wiring looms to ensure a stealth installation.

Take a break - we’re now about half way through the installation. In the final part of the series we’ll mount the ultrasonic sensor, fit the immobiliser relay and integrate remote control locking...