How To: Wiring a LED Bar With Diagram and List

[wake_rider]

Here is a link to a pdf file on how to correctly and safely wire in a LED Bar.

http://static.summitracing.com/global/images/instructions/smt-76246_led%20light%20bar%20wiring.pdf

 

[hrt4me]

thanks!

 

[IBallEngineer]

Here is a link to a pdf file on how to correctly and safely wire in a LED Bar.

While there is nothing "technically" wrong with that diagram, and it IS a safe way to wire, I don't agree with it being correct.

It's a personal preference on my part, and almost ALL Toyota switches not connected to an ECU, but I prefer to switch the ground as opposed to the hot side of the 85/86 combo. Also, I prefer to power that circuit with switched ignition power, so it can't be left on with the key off.

:behindsofa:

 

[wake_rider]

While there is nothing "technically" wrong with that diagram, and it IS a safe way to wire, I don't agree with it being correct.

It's a personal preference on my part, and almost ALL Toyota switches not connected to an ECU, but I prefer to switch the ground as opposed to the hot side of the 85/86 combo. Also, I prefer to power that circuit with switched ignition power, so it can't be left on with the key off.

:behindsofa:

Well, I used this diagram to wire up my light today and no dice. I immediately blew a fuse (30amps) running from the battery to the switch. I replaced the fuse and still I have no light. Using my multimeter I show 12 Volts on the switch at the power in line and negative (ground) terminal, but the output is showing no voltage when the switch is on.

I'm thinking a bad switch? I'm going to go buy another at AutoZone see what happens.

Btw, I used 12 gauge wire all around, two 30A inline fuses, and a 60A relay.

 

[wake_rider]

Well, I used this diagram to wire up my light today and no dice. I immediately blew a fuse (30amps) running from the battery to the switch. I replaced the fuse and still I have no light. Using my multimeter I show 12 Volts on the switch at the power in line and negative (ground) terminal, but the output is showing no voltage when the switch is on.

I'm thinking a bad switch? I'm going to go buy another at AutoZone see what happens.

Btw, I used 12 gauge wire all around, two 30A inline fuses, and a 60A relay.

:redface: Well, I got after it again this morning and realized that I just had the polarity wrong on the switch between the Power Input and the Ground.

It's now working perfectly. Hello brightness! I'm stoked to see what it illuminates tonight...

 

[IBallEngineer]

Using my multimeter I show 12 Volts on the switch at the power in line and negative (ground) terminal, but the output is showing no voltage when the switch is on.

I'm thinking a bad switch? I'm going to go buy another .

Let me see if I understand you correctly, you have 12V at the "power in" AND at the "negative" terminal? Is it a lighted switch? With the switch off you should only have 12V at the "power in", not at the negative terminal. If you grounded that terminal it would blow the fuse. The ground terminal in a switch is generally for the light only. Try the switch with no ground, or just jumper it (touch 12V to output)and see if your light comes on.

:couch2:

 

[piecesparts]

The wiring diagram given is the very basic and it does recommend that the power come from a switched source, so as to keep the circuit de-enrgized with the igntion off. I have wired many circuits, just like that one, however the idea of switching the powered line, vice the ground is also a concern of mine. If the switch for the lights has an internal light to show illumination, then the power would have to go through the switch, you just have to make sure you have the wires right on the switch or you take the 12 volts straight to the ground, vice out to the relay.

 

[wake_rider]

Let me see if I understand you correctly, you have 12V at the "power in" AND at the "negative" terminal? Is it a lighted switch? With the switch off you should only have 12V at the "power in", not at the negative terminal. If you grounded that terminal it would blow the fuse. The ground terminal in a switch is generally for the light only. Try the switch with no ground, or just jumper it (touch 12V to output)and see if your light comes on.

:couch2:

I beat your response by a minute! Lol. Yes, it is a lighted rocker switch, ergo it's a 3 terminal switch so there's the need for a ground.

Switching the polarity fixed the problem.

The wiring diagram given is the very basic and it does recommend that the power come from a switched source, so as to keep the circuit de-enrgized with the igntion off. I have wired many circuits, just like that one, however the idea of switching the powered line, vice the ground is also a concern of mine. If the switch for the lights has an internal light to show illumination, then the power would have to go through the switch, you just have to make sure you have the wires right on the switch or you take the 12 volts straight to the ground, vice out to the relay.

I'm certainly not against having the power input come from a switched source, heck, I'd prefer that so that the circuit isn't live while the car is off. As you said though, the diagram is very basic and that explains my electrical skillset and experience: "basic." As such, I really don't know how to wire into a preexisting switch, and tapping into the factory power has me a little intimidated.

 

[TheeMikeB]

While there is nothing "technically" wrong with that diagram, and it IS a safe way to wire, I don't agree with it being correct.

It's a personal preference on my part, and almost ALL Toyota switches not connected to an ECU, but I prefer to switch the ground as opposed to the hot side of the 85/86 combo. Also, I prefer to power that circuit with switched ignition power, so it can't be left on with the key off.

:behindsofa:

What is the benefit of switching ground vs switching hot?

 

[IBallEngineer]

What is the benefit of switching ground vs switching hot?

By switching ground you run virtually only milliamps through the switch, thereby eliminating heat and failures. Truly though, if you use a bosch type relay, the current draw on the coil circuit is so small there is really no problem switching the power side.

The other benefit is you don't have a power circuit running between your switch and relay, which in some cases involves going through the firewall and up in to the dash. A 16 or 18g wire instead of 12 or 14g wire. Not huge but if you are running say 6 or more it becomes a much bigger harness. Like I said, its a preference for me.

:couch2:

 

[Socco]

Good lord! You don't need a 20A circuit to energize a relay. 3A is more than adequate.