Headlight Wiring Diagram With Relay

First im running new twelve gauge wires and using relays in order to upgrade my factory headlight wiring so that i can use higher wattage headlight bulbs.

Headlight wiring diagram with relay.
First study the 3 diagrams that you will use as your guide on how you want to built your wiring.
If you do not install a relay and use a switch you could end up overheating the switch melting the wires and reducing the current that is getting to your lights making them less bright.
I did this for two reasons ease of access not hidden by the battery and its close to where the headlight wiring comes from the fendercab.

Ok so lets get to wiring.
How to wire your light using a relay the relay will have 4 points on it marked 30 87 85 and 86.
Place the fuse holders immediately after the connection to 12 volts to protect all your wiring.

How to wire up lights in your hotrod.
After you have all the things and tools you will use now lets make a headlight wiring relay kit.
Headlight relays diagram included hello im currently in the process of doing a couple things to my headlight wiring.

Use the white and yellow wires that went to the stock left side headlight bulb to supply the trigger signal for your relays.
This is accomplished with relays which use the original headlight power wires as switching leads only.
Also im trying to p.

The alternator output post is a great place to get your 12 volt supply.
For anything above 30w we recommend installing a relay.
Upgrading your headlights with bosch relays for brighter lights as part of the wiring upgrades on my car im also installing a set of headlight relays to take some of the load off of the oem wiring setup so that the headlights will run brighter.

The main power from the battery feeding the fuse and relays should be a nice large gauge wire as indicated.
The wiring diagram below shows what you need to end up wiring to make this work so if you know how to read a wiring diagram and feel like skipping ahead just go click on the thumbnail for the wiring diagram and check it out in full size full color glory.
Knowing where i wanted to put the relays i could set the length of wire i needed to power up each relay as well as the ground wires for the relays.

1measure the lenght of the wire you need from the stock wiring going to the left to right if your battery is in the right then your wiring should start in right headlamp going to left.
Its set up for a basic system.
The wiring diagram below will get you good bright lights without overloading the switches and wiring.