Light bar wiring help

So I'm wiring up a new light bar I got, and one of my grievances with it is the switch. I hate flicking it on and off if I'm driving on road with it on and theres a car coming. I know they're illegal on road but I live in a rural community and I use it when I'm not on the main highway so I can see any deer in the road. I would like to wire it into my brights switch. So that when the switch for the light bar is on, and I switch my bright on, then the light bar will also come on. But if the switch is off and I switch my brights on, then only the bright come on. Is this possible? And if so, does anyone have any recommendations on how to do it?

 

I think that switch won’t be able to handle the amps, if you mount light bars at the same level or lower then your head lights and as long as there isn’t more then 4 lights on in the front you xan legally drive with them on and call it fog lights. Atleast that is what i read in the vehicle law book for lights here in California

https://law.justia.com/codes/california/2010/veh/24400-24411.html

 

I did this, you need to switch it through a relay. Then drive the relay with a 3 position switch (Double throw, center off). On the switch, Common drives the relay coil, and one switched terminal goes to +12V constant, the other to the high-beam lead which can be tapped under the dash. Can't recall what color it is but study the wiring diagrams in the FSM to find it. You should also tap the 12V constant form the same circuit which will be in the same bundle of wires. I put the relay near the battery, and of course fused the tap going to it. Let me know if you need more info.
When you are done, it's an awesome setup. I almost always leave mine on the high-beam position.

 

Yep, simple relay. Switch powers the relay, the high beams is the trigger. Except for the switch wiring, everything can be done under the hood.

 

Awesome! is the 3 position switch mandatory for this? or can i just use the same on/off switch I'm using now?

 

On/off is all you need. But you could use a a dpdt and be able to bypass the Hugh beams.

 

You can use a single throw (on/off) switch but then you would just have off - and - on if the high beams are on. No “on no matter what” position.

Truthfully I almost never use the “on no matter what” position on mine!

 

Thanks for all the help guys!

 

One thing that no one has mentioned is the fact that most earlier model Toyota headlights are ground switched. The only exception to this with 1st gen Tacomas is if you have daytime running lights. You will not find a 12v+ trigger when the high beams are on and you will need to wire your relay differently than you would normally think.

The headlights work by grounding either the low beam or high beam filament. Therefore, both hi and lo have 12v once you turn the headlights on.

Here is one way to wire it. Your ground trigger source is the ground wire for the high beams. You can also put a switch in-line to this to disable the light bar whenever you want. If you wired it like a few people have mentioned above (unless they have DRL), then you will be back feeding power into the other headlight filament and lighting both filaments at the same time.

 

I imagine the only way to wire the relay is to splice high beam wires at the headlight bulb. So the relay would be triggered only when high beam is on. For independent light I imagine three way rocker with two sets of contacts like described above by MikeWH.

 

Here is the mock-up diagram based on 2001 but headlight connection did not change since 95.



When connected as shown 3-way switch works as follow: at the switch position as shown the LED bar is turned on independently. At the center position the LED bar is turned off. At the last position Let Bar will turn on when high beam is on (also in the "flash" mode). The only splice to the existing circuit is at either headlight connector (you can use H4 extension and splice it if you don't want to cut factory wires).

This is exactly how I wanted to wire my LED bar in my Bismarck, but I wanted to use "factory looking" switches, so I will have to go a different route. But when I finally figure out how to put a LED bar in my Tacoma, this will be the diagram I'll use.

 

Yup. Just like this would be perfect. Just add the switch Here to disable the light bar if you need to:

 

It would be better to put the switch between the 86 terminal and power, or 85 terminal and high beam wire (ground trigger source). This way you won't be running your full load through the switch. In that diagram 86 and 30 are connected together, but they don't need to be. Your 86 power source can be any 12V circuit. 30 needs to go to the battery.

 

Yup that would work too, but I personally would use a high amp switch in line with the circuit after the fuse so I knew I turned off power to the circuit completely. I've seen solenoids/relays fuse in the on position.

User preference

 

Looking at the headlight diagram this will not work if you want to use high beam stalk as a "ground trigger source". At low beam position with headlights off the current will flow from the relay 85 via headlight bulbs (both filaments) to ground via low beam stalk (which will be closed). The resistance of headlight bulb is negligent for the relay.