Amps and accessories

Try to use Ohms Law E=IxR and P=IxE
P (Power)= I (current) x E (volts)
Watts/Volts = Amps
18/12 = 1.5A each 18W light
12/1.5 = 8 ohm resistance each

The stock headlamp on mine is rated at 60/55W 5A

Keep in mind the current draw on the same wire would be additive! Most accessory circuits are rated at 15A, the wiring/fusing has to be rated for all the goodies you have on the circuit.

My light kit arrived came with a 40A harness and integrated waterproof switch with stick-on adhesive backing. This harness has two circuits a low amp control circuit and a high amp lighting circuit.
The controls circuit is powered by the accessory plug so when the key is switched off the "off" light is illuminated; it’s grounded thru that plug. the 40A circuit is energized by the controls circuit "on" switch and connected directly to battery. That way you’re not overloading the accessory circuit with a high draw accessory—same way you wire a winch.
The one problem I had is that the my older TRX battery is placed well behind the seat so the battery lead was too short.
The on switch came with adhesive backing so stuck it on the back of the headlight bucket