Product: Single trumpet Train Horn + 12V compressor
Fitment: For cars, trucks, boats, motorcycles and other vehicles with 12V power supply
Package Includes: Single trumpet Train Horn, 12V air compressor, air hose, bag of fixings
Working voltage: 12V
Working current: 20A
Before the installation:
- Please install the horn following these instructions.
- Power off your vehicle before the installation.
- (Optional) Disconnect the old horn wires before the installation.
- In order to minimize the voltage loss, make the wires as short as you can.
- IMPORTANT! In order to minimize the efficiency loss, use wiring that can support 15-20A of current. We suggest using 12 American wire gauge (AWG) thickness for main power for each compressor.
- In order to make the horn work well, make the air tube as short as you can.
- Make sure the air tube has free air flow and isn’t blocked by bending it.
- Keep the air compressor away from a direct contact with the engine and other vehicle components that produce a lot of heat.
- Air compressor should be installed vertically (up and down position)
How to install (as shown in the pictures below):
- Screw the air compressor and the horn to the place you want to install it to. Suggestion: Install the horn trumpet downwards, so that it prevents water getting into it.
- Do the wiring. The positive side of the air compressor connects to the “+” side of the power, the negative side of the air compressor connect to the “-” side of the power.
- Connect the air compressor and the horn by using the air tube.
- There are 2 ways to do the electrical wiring, explained below.
Single horn. VERSION 1 of the connection (MOST BASIC):
This circuit requires straight power from the battery and a separate switch/button that can handle 15-20 amps of current.
Shopping list: 12 gauge wire, 20-40A inline fuse, 20A switch/button. You can get all of these from any automotive store.
Your horn would be inefficient if you use thin wiring and low voltage power from other accessories. We suggest using 12 gauge wiring.
- Wire power from the battery “+” to your switch/button in the car. Also install a 20-40A fuse closer to the battery on this wire for safety reasons.
- Wire the power from the other side of the switch to air compressor “+”.
- Connect the air compressor “-” to the negative from vehicle chassis/body. You can also wire it to the battery “-”.
Attention to pay to using this method: Your switch/button needs to support ~20A current due to being directly connected to 12 gauge wire. If you want to use thin wires for the switch or use the stock horn button as the switch, see VERSION 2.
Single horn. VERSION 2 of the connection (ADVANCED, BUT BETTER):
This circuit is a bit more complicated, but it can be powered by a low current switch/button or by the stock horn button. If you are new to relays, please also watch the video at the bottom.
Stock horn button shopping list: 12 gauge wire, 20-40A 4 or 5 pin relay, 20-40A inline fuse. You can get all of these from any automotive store.
New switch/button shopping list: 12 gauge wire, 20-40A 4 or 5 pin relay, 20-40A inline fuse, any switch/button, 18 gauge or smaller wire for the switch, (optional) 5-10A inline fuse for the switch wiring. You can get all of these from any automotive store.
Using a 20-40A 4 or 5 pin relay. This connection is better as the switch can be used with lower current (thinner wires) to connect the 12V circuit via the relay. Relay is basically a magnetic switch activated by smaller current.
Relay pins are universal and have the same number markings:
- Use 12 gauge wire: Wire power from the battery “+” to pin number 30. Also install a 20-40A fuse closer to the battery on this wire for safety reasons.
- Use 12 gauge wire: Wire negative from vehicle chassis/body to pin number 85. You can also wire it from the battery “-”.
Now we need to power our switch/button (or you can wire it to your old horn button/wires):
- Use 18 gauge or thinner wire: Your switch needs a positive power source. You can take this from the battery “+” or from somewhere from the dash wiring. If you wire it from the battery, install a 5-15A fuse closer to the battery for safety reasons.
- Use 18 gauge or thinner wire: Wire the power from the other side of the switch to relay pin number 86.
4.1. If you want to use the existing horn button, then find the horn wires and from those wires, connect the positive to the relay pin 86. No additional fuse is needed here.
Now your switch/new button is installed. Lets do the compressor connection:
- Use 12 gauge wire: Connect the air compressor “+” to relay pin number 87.
- Use 12 gauge wire: Connect the air compressor “-” to ground from vehicle chassis/body. You can also wire it to the battery “-”.
- If you used 5 pin relay, the 5th pin can be left blank.
Well done! Your horn is now ready to use.
Here is a link to two YouTube videos that explains relay and connections to it really well, these video are not ours: