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Installation manual for the Wolo Bad boy / Big bad Max, Wolo Bandido dual air tone horn / MC Airsplitter / Power House / Silver Streak, Wolo Marine horns, Stebel Nautilus / Truck, Stebel GP(A)2 / GP(A)3, Stebel VM2 / NM2.



  • Before starting the installation, the battery needs to be disconnected. First disconnect the mass (-) connection and only then disconnect the plus (+) connection. This minimises the chance of a short circuit. Make sure that the cables will not accidentally rebound off the battery poles. A folded towel in between should suffice.

General instructions

  • Use a wire of at least 2.5 mm2 to connect the horn.
  • Use fitting, isolated faston plugs and clips. Clasp this onto the wire using the correct tools. The plugs should be fastened in such a way that they cannot be disconnected from the wire by hand.



  • Make sure that the wires cannot be damaged mechanically. Secure them with binding straps. Pay extra attention to places where they might come into contact with sharp elements of the frame.
  • Always make use of the included relay. The horn uses 18 Ampere. A standard horn switch cannot process this power and will quickly burn out.
  • Place the relay with contacts facing down where water and dirt can reach it as little as possible.
  • In the installation manual, we work with coloured wires. Naturally, you can use all black wires, but that does mean you will have to be more careful.

Installing a horn with built-in compressor

  • Remove the old horn.
  • Place the new horn where water and dirt can reach it as little as possible. Place the new horn upright as much as possible, at an angle of no more than 25 degrees.

Installing a horn with separate compressor

  • Remove the old horn.
  • Install the air horns horizontally or with the opening pointing slightly downward.
  • Find a place for the compressor in the immediate vicinity of the air horns. Install the compressor upright as much as possible. Place the compressor where water and dirt can reach it as little as possible.
  • Connect the air horns to the compressor by using the included hoses. Keep the hoses short and prevent sharp curves. Subsequently make the connections as indicated on the packaging.
  • Make sure that the parts are not placed too close to warm objects, such as the radiator.

Electric connection

Find a place to install the relay. The place of the old horn is probably fine, as long as the relay cannot be damaged by water and dirt.

Move or extend the 2 wires that went to the old horn and connect these to the connections 85 and 86 of the relay (order does not matter). In order to extend the wires, you make two pieces of wire with faston males on one side and faston females on the other.


Remark: If the old horn only has 1 connecting wire, it uses the frame as mass. In this case, the wire should be connected to connection 86 of the relay. Subsequently connect a short piece of wire to one side with a faston female and to the other side with a faston eye. Move the faston female to connection 85 of the relay. Screw the faston eye onto a spot on the frame (mass). The place of the old horn is a good spot. Use a knurled ring to secure a good electrical contact. Such a ring has probably turned up when removing the old horn.

Draw a (black) wire from the minus (-) connection of the compressor of the new horn to a suitable mass point. This should preferably be the mass (-) connection of the battery. Clasp a faston eye to the battery side and a faston female to the other end of the wire.

Draw a (red) wire from the plus (+) connection of the compressor of the new horn to connection 87 of the relay. Place faston females of both ends of the wire.

Draw a (red) wire from connection 30 of the relay to a place near the plus (+) connection of the battery. Place a faston female on both ends of the wire.

Connect the wire to the fuse holder of the floating fuse to the battery side. You can stick the fuse holder to the side of the battery with double-sided tape. Place a 25A fuse in the fuse holder.


Place a (red) wire between the plus (+) side of the battery and the floating fuse. Make sure that this wire is as short as possible and is mechanically well protected. Clasp a faston female on the fuse side and a faston eye on the battery side.


Reconnect the battery, including the new wires. It is safest to first connect the plus (+) and then the mass (-) side. Put back the protective caps on the battery poles.


Now, the switch can be turned in the contact and the horn can be pressed.


Installation scheme