Usually used in engines with PLNs, like nitrous oxide, a Hobbs switch, manufactured by Honeywell, regulates pressure and prevents dangerous pressure overloads. A Hobbs switch connects in series a type of electrical circuit, between the engine's throttle switch and the boost system. When activated, the boost system delivers a powerful fuel additive to the engine. When the engine receives the additive, its internal pressures rise. A Hobbs switch will automatically turn the boost system off once the engine's internal pressure reaches a certain level.
Run a 14-gauge wire from the throttle switch to the Hobbs switch. The throttle switch, often a push-button or toggle switch, turns the boost system on and must have an amperage rating exceeding the boost system's amperage rating. Check the boost system's solenoid rating to find the system's amperage rating.
Cut the 14-gauge wire at the Hobbs switch with wire cutters. Leave an extra 2 inches on each end of the wire.
Strip 1/2 inch from each end of the 14-gauge wire with wire strippers.
Wrap the end of the 14-gauge wire that leads to the throttle switch around the throttle switch's wire terminal and tighten the terminal screw with a Phillips screwdriver.
Wrap the end of the 14-gauge wire that leads to the Hobbs switch around one of the Hobbs switch's wire terminals and tighten the terminal screw with a Phillips screwdriver. The 14-gauge wire can connect to either wire terminal.
Run a 14-gauge wire from the Hobbs switch to the boost system and cut the wire with wire cutters. Leave an extra 2 inches of wire on each end. Depending on the manufacturer and the installation, the wire leading to the boost system will either connect to a relay or a solenoid.
Strip 1/2 inch from each end of the 14-gauge wire with wire strippers.
Wrap the end of the 14-gauge wire that leads to the Hobbs switch around the Hobbs switch's second wire terminal and tighten the terminal's screw with a Phillips screwdriver.
Connect the wire that leads to the boost system's relay or solenoid to its proper wire terminal.
