Wiring LED lightbar to high beams

I am trying to wire my lightbar so that i have the option to have it on at any time, off, or come on with the high beams.

As i understand it, i need a SPDT switch to acheive this. One on position will be wired directly to a power source (with a fuse in line). This will allow me to have the light on at any time, regardless of if the truck is on. The other on position will be tied into the high beams. As i understand it, i just need to tap the high beam wire with one coming from the switch. I am assuming that i will need a fuse in this line as well?

I have been researching this and a lot of people keep talking about tying into a relay somewhere? Do i need one to acheive what i am looking for?

Am i overlooking anything in this setup?

 

This.

Just go with a basic switch install for now. Less headache. As you get better with wiring over time then you can upgrade to a more complicated setup.

 

Right forgot to mention it will be grounded


I guess i didnt make myself clear. The SPDT switch will be in the cab. It will be on/off/on. One on will be hooked to the battery. The other wired into highbeams.

 

A buddy of mine has the setup your describing with an on/off/on switch so I know it's possible. I've wondered how it's done as well but he doesn't know either b/c it came with his rig already setup. Wouldn't mind wiring my led light bar like this. I'd maybe shoot OTRATTW an email or post a question on their facebook wall. They'll probably know.

 

Sub'd

 

First off, if you want to have a on/off/on option where you can have the light bar turn on by battery power, be off completely, or be on by the highbeam switch, you can't use a SPST switch. you will need a DPDT switch, which has an on/off/on switch position setting. A SPST switch is basically an "on/off" switch, which while it can be adapted to something SIMILAR to what you want, it would only allow your lightbar to be on by battery control, or on by highbeam control, and NOT turned off completely.

This can be done reasonably easy, but I would recommend doing this with a relay. Simply because it is always safest to do it this way. You will hook up your switch just as you had said, with one input coming from a fused battery source, and the other input coming from the highbeam signal from the switch. You then take the OUTPUT signal from the switch and connect it to the control side of a relay (typically called "terminal 86"). Then ground the correct terminal of the relay (typically called "terminal 85") to a good ground. This will energize the relay dependent on if you have the in-cab control switch on the battery side, or the highbeam side. Then you will have the higher current fused battery wire connect to the relay power side (typically called "terminal 30") and the output side (typically called "terminal 87") will go directly to the lightbar power. Then ground the lightbar ground wire to the chassis. Once this is done, you will have your "on/off/on" option that you are looking for.

 

Ah sorry, I dont know why I kept putting SPST... i meant SPDT.... Would that work?

Basically, one of the on positions on the switch would be wired like this and the other like this I believe the diagrams on these threads illustrate what you are saying.

 

If you use a SPDT switch you can do it. If you want some help figuring the SPST and other switches like that, this is a good source of information. You do have to be careful in making sure it has the proper switch positions where it has an on/off/on positional setting.

Your links took me to two different threads, but not the specific posts you were wanting to mention. When I get a chance tomorrow I will draw up a diagram to do what you are wanting it to do, if you would like.

 

I know I would appreciate the diagram. I already have the standard off/on, but want to run a front and rear lightbar like above. What is that switch you're talking about? And which wire is the one to tap for the high beams?

Thanks.

 

A diagram would be awesome if you have the time! Stuff like this makes the most sense to me in a visual presentation.

 

Pugga has this exact setup with the on/off/on switch, and i think he had a diagram

 

http://www.tacomaworld.com/forum/technical-chat/247940-wiring-diagram-check.html

 

Make sure you're using a relay. Steal power for the low current side of your relay, from the high beam power wire. Then when you flick on your high beams, your LED bar relay powers up and that comes on too. The low side of a relay runs such low current it won't affect your high beam circuit.

 

Mentioned already. lol. Good to reemphasize though.

The diagram from the link does show the proper way to wire the switch itself. I was very busy at the shop today, so I will do my best tomorrow to get you an entire wiring layout.

 

Quick and dirty using relays:

 

Bah I didn't read, I just write

 

On the SPDT switch, the key is that the center connection goes to your LED light bar or the relay that powers the lightbar. The connection at the top of the relay receives power from Accessories power, the bottom connection goes to you power source that is on when the hi-beams are on.

 

That must be really quick and very, very dirty No need for 2 relays and it is generally not a good idea to run your power for the accessory through the switch. Many switches aren't meant to handle that kind of power and you want to keep the high power in the engine bay, not running it back and forth through the firewall. While your diagram would technically work if everything was properly rated for the power the light bar requires, I wouldn't go that route, sorry.

My ears were burning!

^^ From that thread, look at this post.

This is a DPDT switch, like I used but it can be done with a SPDT also (basically the single pole, double throw switch will only have one side of this diagram and the switch lights will likely be connected internally a little different). For a SPDT, look at numbers 1, 2 and 3. These switches and the diagrams you find online for them assume you're bringing power in from one spot and then it will be outgoing in the 2 on positions. You will be doing the opposite.
On the diagram above:
Pin 1 would be fused power from the battery (I'll come back to this because you don't want the light bar drawing full power through the switch)
Pin3 3 would be your high beam tap (this does not need to be fused since the high beam circuit is already fuse protected)
Pin 2 is outgoing to your relay

On your relay:
85 - Ground
86 - comes from Pin 2 on the SPDT switch (this is what activates the relay to turn on)
30 - fused battery power. What I would do is take power from the battery, run it through a fuse, then split it. One wire goes to the switch like mentioned above, the other wire goes to pin 30 on the relay. That prevents the light bar from pulling full power through the switch.
87 - outgoing power to the light bar.

At the light bar, the wire coming from 87 is your power in so all you should have left to do is ground the light bar itself.

Obviously, depending on the switch you end up using, you might need to tweak what I wrote above but hopefully you get the idea. Once you decide on a switch, post up the wiring diagram for the internals of that switch and I can tell you what needs to be connected where.

 

Is what you stated above for a SPDT switch with independently wired lights? I would prefer only the upper light to come on when upper position is pressed and vise versa for the other side.

 

If the lights are wired independently, then you will need to do something a little different. The diagram I posted was for a DPDT. Do you have the diagram for the SPDT with independently wired lights? I haven't wired one before but what you're saying could be accomplished probably with a couple jumper wires.