CT-V03 Installation Guide + Wiring Diagram
Installation of the CT-V03 requires a minimum of 3 wires to be connected to your vehicle’s electrical system. A 4th wire is optional — it enables remote fuel/power cut-off through the supplied relay (see step (3.1)).
Warning/Disclaimer: We recommend hiring a professional auto electrician to install your new GPS tracker. This guide is intended for auto electricians.
This is a no-solder, reversible install guide. However, you can solder and/or splice the wires however you like, after all, it is your vehicle.
In the box: the CT-V03 tracker, a wiring harness with a plug-in connector, a 12/24 V relay and a screwdriver.
(1) Install SIM Card
ℹ️ Your tracker usually arrives with its SIM card already installed and activated — if so, skip straight to step (2). Only open the case if you’re fitting your own SIM.
Activate a new SIM card and install it into the tracker. The CT-V03 takes a nano-SIM (the smallest size).
ℹ️ Bringing your own SIM? Some networks need an APN set on the tracker before it will connect. Contact us and we’ll walk you through it — it takes a minute.
⚠️ The case is sealed for water resistance and held by internal clips as well as the two screws. Open it only with a plastic pry tool — a phone-repair spudger or a guitar pick — never anything metal. Careless opening can damage the seal.
- Remove the two screws at the cable end of the case.
- Slide a plastic pry tool into the seam and work it around the case with firm, steady pressure, listening for the clips clicking free as you go, then lift off the cover.
- Make sure the internal battery switch (next to the SIM slot) is OFF.
- Slide the SIM holder to unlock it, flip it open, seat the nano-SIM, close it and slide it back to lock.
- Flick the battery switch to ON.
- Refit the cover — press until the clips click home — and tighten the two screws.
⚠️ Before removing or inserting a SIM card, make sure external power is disconnected and the internal battery switch is OFF.
(2) Locate Wires
A minimum install requires finding 3 wires in your vehicle. The colours below are the vehicle’s typical wiring — not the tracker’s harness colours (those are in step (3)) — and they vary between makes, so always confirm with a multimeter:
| Vehicle Wire | Description | Typical Colour — Car |
|---|---|---|
| Ground (-) | Constant Negative | Black |
| Permanent Power (+) | Always On Positive | Yellow |
| Ignition (+) | Key Switched Positive | Red |
The ‘Ground’ is typically the body of the car, any exposed metal and bolts that pass through the body of the car will be sufficient.
Identify ‘Permanent Power’ using a multimeter. Remove the keys from the car. Connect the black probe to the vehicle body (ground) and use the red probe to locate a 12VDC or 24VDC power source.
Identify ‘Ignition’ using a multimeter. Insert the key and turn it to the ON position (dash lights on, engine off). Connect the black probe to the vehicle body (ground) and use the red probe to locate a 12VDC or 24VDC power source. Upon finding a power source, switch the vehicle off — if the voltage drops to zero then you’ve found the ‘Ignition’ wire, if it remains on then you’ve located a ‘Permanent Power’.
(3) Install The Wiring Harness
The CT-V03 harness has 4 colour-coded wires, matching the interface diagram printed on the tracker:
| Tracker Wire | Connects To Vehicle | Notes |
|---|---|---|
| Red (VCC) | Permanent Power (+) | 9–90 VDC — suits 12 V and 24 V vehicles |
| Black (GND) | Ground (-) | Vehicle body or battery negative |
| Orange (ACC) | Ignition (+) | Powers the ignition on/off alerts and trip history |
| Yellow (Relay) | Relay coil (optional) | Only for remote fuel/power cut-off — see step (3.1) |
⚠️ The tracker’s wire colours are not the same as the vehicle’s typical colours in step (2) — in fact they collide: the vehicle’s yellow is usually permanent power, but the tracker’s yellow is the relay wire. Never connect the tracker’s yellow wire to vehicle power — wire by function, not by matching colours.
📝 The red wire comes with a 1 A inline fuse already fitted — keep it in circuit, positioned as close to the power source as practical.
⚠️ Disconnect the vehicle battery before you start!
⚠️ Unplug the wiring harness connector from the tracker before you start!
Connect the ‘Ground’ wire
| Option(s) | Installation Notes |
|---|---|
| Ring Terminal (Preferred) | Bolt the wire to the body of the car using a Ring Terminal |
| Splice Connector | Identify wire gauge and use appropriate size connector. |
| Wire T-Tap Connector | Identify wire gauge and use appropriate size connector. |
Connect the ‘Permanent Power’ and ‘Ignition’ wires
| Option(s) | Installation Notes |
|---|---|
| Splice Connector | Identify wire gauge and use appropriate connector. |
| Wire T-Tap Connector | Identify wire gauge and use appropriate size connector. |
📝 Insulate any introduced exposed wire or metal, including un-used tracker harness wires.
⚠️ Connect the vehicle battery and double-check the tracker wiring harness.
✅ Plug the harness connector into the tracker (line up the arrows on the connector) and cable tie the tracker firmly with the labelled side facing the sky.
The GPS antenna is inside the case, under the labelled face — it must point up, with no metal above it. Behind or under the top of the dash and under the rear parcel shelf both work well. Avoid mounting under metal panels or heat-reflective / metallised windscreen coatings, which block GPS signal.
(3.1) Relay Wiring Diagram — For Fuel/Power Cut-off (Optional)
The supplied 12/24 V relay lets the CT-V03 remotely cut the vehicle’s fuel pump (or another circuit) — for example after a theft. Wire it in series with the fuel pump’s supply wire:
| Relay Terminal | Connects To |
|---|---|
| 86 (coil) | Tracker’s Yellow wire |
| 85 (coil) | Power (+) — tap the supply side of the cut wire |
| 87a (normally closed) | Supply side of the cut fuel-pump wire |
| 30 (common) | Fuel-pump side of the cut wire |
Cut the fuel pump’s supply wire, then make all four connections in the table: supply side to 87a, pump side to 30, and the relay coil fed by 85 (to power) and switched by 86 (to the tracker’s Yellow wire). With the relay at rest the circuit is closed and the vehicle runs normally; when a cut-off command is sent, the tracker energises the coil and the circuit opens. After installing, test a cut-off command with the vehicle parked and confirm the engine won’t start.
⚠️ Only ever activate fuel/power cut-off while the vehicle is stationary. Cutting fuel to a moving vehicle is dangerous.
(4) Verify The Tracker Is Working
Method 1 — Lights
Park the vehicle outside with a clear view of the sky and turn the ignition on. The first GPS fix usually takes under a minute. The CT-V03 has three status lights, visible on the labelled face:
Power Status (Red)
| State | Meaning |
|---|---|
| On for 0.1s and off for 3s | Working correctly |
| Solid on | Internal battery charging |
| On for 1s and off for 3s | Internal battery fully charged |
| On for 0.3s and off for 0.3s | Internal battery low |
| Off | Lights timed out (see note below) — or internal battery flat / internal fault |
GPS Status (Blue)
| State | Meaning |
|---|---|
| On for 0.3s and off for 0.3s | Searching for GPS signal (if longer than 1 minute, move to open ground) |
| Solid on | Positioning success |
| Off | GPS sleeping, or lights timed out (see note below) |
Network Status (Green)
| State | Meaning |
|---|---|
| On for 0.3s and off for 0.3s | Initialising |
| On for 1s and off for 3s | Network signal OK |
| On for 0.1s and off for 3s | Device online |
| Off | No mobile signal or no SIM card, or lights timed out (see note below) |
ℹ️ The lights switch off automatically once the tracker has been running normally for a while — dark lights on an installed tracker are normal. To re-check them, unplug and re-plug the harness connector: all three lights come on for 3 seconds, then show the states above.
Method 2 — Tracking Platform
Log in to the tracking platform at platform.crucialtracking.com.au and confirm the tracker is online and reporting its position. Drive around the block and watch the position update. If it doesn’t come online, check the SIM is active, the harness connector is seated, and the red wire has permanent power.