Honda GL1800 Front Mount Air Horn Installation Instructions
1. Place the motorcycle on the centerstand.
2. Remove the left side cover (painted) to expose the battery. Remove the left plastic engine cover (chrome). Remove the lower center fairing cowl or spoiler; there are 2 pull pin rivets and 6 allen screws holding this panel in place. Drop the panel down and slide it out to the right or left.
3. Horns and Mounting Bracket: Attach the large “L” shaped bracket with the split clamp to the engine guards as shown in photo #1. NOTE: Make the screws snug only! Install the horn set onto the “L” bracket using the 2 allen screws provided, tighten securely. Align the horn set to be level and to have clearance between the fairing as shown in photo #2, tighten securely.
4. Compressor: Remove the stock left hand horn and loosely re-install the 12mm mounting bolt (see photo #4A). Next as shown in photo # 3, to the compressor attach the air hose, the short red wire to the (+) positive terminal and the white wire to the (-) negative. The mounting bracket should be bolted to the compressor as shown. Install the compressor assembly as shown in photo #4 onto the 12mm bolt and tighten securely. Note! It you may need to adjust the angle or bend of the bracket for a good fit. Try to maintain at least a one-inch clearance between the exhaust header pipe and the compressor, wires and air hose.
5. Relay and Wiring: Attach the red wire from the compressor to the relay terminal 30 (see wiring diagram). Attach the long red wire to the relay terminal 87. Attach the stock horn wires to the remaining terminals 85 & 86 it does not matter which wire goes to which of these two terminals. Attach the white ground (-) wire from the compressor to the lower cowl-mounting bolt as shown in photo # 4B. Cable tie the relay in place as shown in photo #4C. Route the long red wire up and back over the left side of the engine to the battery, This is easiest done using a stiff piece of wire (a coat hanger works good) with a small loop bent at one end. Push the wire from rear of the engine towards the front. Attach the red wire with electrical tape and pull the wire back towards the rear of the engine. Route the wire back to the battery (+) positive terminal, cut the wire to the desired length, strip back insulation 3/8” crimp on the fuse holder provided and attach to the battery (+). Replace the side covers Route the air hose as shown in photo #5 so as not to kink it or be less than 1” from the exhaust, then over the front of the engine, up and out to the horns just behind the engine guards, trim to the desired length and attach to the “Y” fitting. Using a lighter or match, heat seal or melt the end of the hoses braided cover to prevent it from fraying. Turn on the ignition and test the horns.
6. Re-install the fairing lower cowl or spoiler.
7. Thank you for purchasing a RIVCO product.
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