Join Date: May 2018
Location: New Orleans, LA
Liked: 129 times
I agree with Goober, using a relay so you dont overload the factory headlight circuit is a good idea. Regardless if you tie it into the exist headlight or install its own switch a relay should be used.
Go to the local parts store and get a 12v 30amp relay. They may have two different styles, a 4 pin & 5 pin. Both will work but i prefer the 4 pin.
The pins on the relay should be labeled with numbers. The 4 Pin will have 85, 86, 87 & 30. The 5 pin will have 85, 86, 87, 30 & 87A.
*85 goes to ground. Run a wire from this pin to the chassis or negative terminal on the battery.
*86 goes to a switch. Run a wire from this pin and splice it into your exist headlight wire, or to a new switch if you so choose to install one.
*87 goes to the light. Run a wire from this pin and connect it to the positive wire of the light bar.
*30 goes to the battery. Run a wire from this pin and connect it to the positive side of the battery. Make sure you install a inline fuse on the wire as well. The fuse should be closes to the battery as possible.
*87A(if you buy a 5pin) is ignored.
The last wire to connect is the ground wire on the light bar. You will connect this to the chassis or negative terminal on the battery.
Without a relay the light bar will pull all the power needed to light it through the factory headlight wire. The wire isnt that big to start off with so wiring it this way so both lights pull power from it can lead it to overheating and or melting the wire. The harness on the bike has plenty of wires wrapped very closely together so if you were to overheat/melt the power wire for the headlight, chances are it will melt the wires around it too causing a huge headache!
With a relay, which is basically a electronically controlled switch. Instead of pulling all the power needed to make the light work through the existing headlight wire, it uses only a very little amount of power from the existing headlight to activate a solenoid inside the relay, which closes the internal switch. With this switch closed it pulls the power needed for the light directly from the battery.
Hope this helps.
2012 Rancher 420: 25" Maxxis Zillas - Polished 12" ITP Wheels - Custom Retrofitted 5000K HID Projector Headlights With Amber LED Parking Lights - Dual 9” Single Row LED Light Bars - KFI Winch Mount - Badlands 2500lb Winch With Disconnect, 6000lb Synthetic Rope & Aluminum Fairlead - Dry Box Mounted On Fender - Custom Stainless Steel Front Basket Rack - Ceramic Coated
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Last edited by Z7What; 11-09-2018 at 02:28 PM.