If you want to know how to wire high and low beams together so that while turning on the high beams, both high and low beams should be ON at the same time, but in the case of low beams, there should be no effect, and beams should be functioning the same, you are at the right place.
Essentially, you are doing that to get more light on the road. Therefore, with just the original lighting, you probably need to consider figuring out how to wire it so that the fog lights will turn on when your high beams are activated. This could be a better option. But on the other hand, you may have a vision problem because fog lights can disturb your night vision. However, it’s a considerable option.
Let’s look at the actual answer with the actual procedure and step by step instruction to the question of how to wire high and low beams together?
How to Wire High and Low Beams Together?
By sending a reference voltage to the headlamp switch, the vehicle’s computer determines the resistance that will be added to the circuit based on the position the switch is in. As soon as the circuit returns to the computer, it will compare the voltage it received with the voltage transmitted before.
Then this information is used in the decision-making process on what lights to turn on based on the program that was installed on the computer.
Step 1:
In order to Wire high and low beams together, first of all, you are required to purchase one standard 4-prong relay for this project. It is also fine to use a 5-prong relay, but terminal #87A will not be used, so if you are buying a new one, the 4-prong relay is recommended.
Step 2:
Additionally, some wiring and a variety of electrical terminals, as well as 2-diodes, will be required.
Basically, you will be using the high beam power wire as a trigger for a relay, which will then supply power to the low beams.
Step 3:
There is a suggestion that you do this on both sides (2 relays, one each to the left and right; they will be wired in the same manner.) You need to locate the high beam power wire (one of the wires is white or light green, while the other is gray or white). After that, simply tap into the wire with a scotch lock or connect a wire to it.
Step 4:
Many people think that Scotch locks are a really bad idea because they can cause a lot of problems in the future. It is highly recommended that you attach the wire from the high beam to terminal #85 on the relay.
Step 5:
You will also need to attach another wire from terminal #86 to a good ground.
It is now time to find the wire that leads to the low beam (left – black or dark blue, and right – white or tan) and cut it. Then the diode must be installed with the arrow pointing in the direction of the headlight.
As far as I’m concerned, diodes that have the same size as fuses are the best choice because all you need is a fuse holder inline, and then you can install a diode in place of the fuse.
Essentially, the diode allows the computer to send voltage to the low beams, but it will also prevent receiving power from the computer to low beams when you are using the high beams. So, there will be no damage and burns.
Step 6:
In order to complete this installation, you will need to connect a wire between the diode and the headlight. The wire needs to be attached to the relay’s terminal #87; if you are using a 5 terminal relay, make sure you connect it to terminal #87 and not terminal #87A.
Step 7:
Last but not least, we are going to connect a wire from our battery to terminal #30 on the relay. The reason for doing this is that the battery has an inline fuse of 30 amps, but the computer controls the virtual fuse for the headlights.