Wiring extra reverse lights to switch and preexisting lights

Curious to know what goes into doing this.

I've acquired a pair of LED lights that I want to add to the reverse lights I already have, but I also want to add a switch to turn them on without putting it in reverse. I'm handy enough to accomplish it, I just don't know electrical all too well and what exactly would be involved. I know to splice in to the reverse wire, but I'm not sure about adding a fuse for a switch in the cab and such.

Anyone have experience doing this or someone that can just help out?

Thanks

 

use a relay with two wires going to the switch side of the relay. One wire goes to your manual switch so you can turn it on anytime, the other will tap into your reverse light circuit. In that wire, install a diode so that when you flip the manual switch, your reverse lights don't come on.

 

SPDT, 3 position switch (on-off-on) in the cab. Two incoming fused power sources, one tapped to reverse light wire in the cab, the other from another positive power source, either a new one run into the cab (on anytime) or tapped to a circuit that's hot on ACC.

SPST relay, one separate fused power source from the battery to the 30 pin, 85 pin to ground (-), 87 pin to lights, load/power out wire from switch to the 86 pin. You will have the ability to have the lights off, on with reverse, or on (with ACC or anytime if you run a new wire).

 

Wow so much confusion going on in here lol. I'll make a diagram for you now. OP, do you have a backup camera? If so, I can make it so that when you manually turn the lights on with the switch, that it will trigger you camera to turn on.

 

This is the simple way...



Removing the "diode" from the wire that taps into your reverse lights will cause your reverse lights to come on whenever the switch is turned on for your aux lights. This is bad because they will not be receiving sufficient power. Also, that would cause your dash to illuminate the "R" on the PRNDL display and make your truck think its in reverse... not good. So make sure you keep the diode there.

Option 2 would be a 3 way switch which allows you to choose:
-manually on
-always off
-on when in reverse

If you want to see that diagram all make that one too. Pick one and I can make a better one online showing more details including fuse and diode amperage and stuff.

 

That's exactly what I was referring to. Just don't have the ability to put up a diagram on my work computer.

I would also go one step farther and used a 12volt signal that is only hot when the key is on for the switch. That way if you leave the switch on when you turn off the truck, you won't accidentally kill your battery.

 

This is option 2 with the 3-way switch idea. I forgot to draw the diode but make sure its there (I wrote where it goes).

Also, if you have the backup cam and want it to turn on when you turn the lights on, then instead of taping into the (+) reverse light wire for your trigger, you can tap into the (+) 12v wire which feeds power to your camera instead. By doing that and not using any diode, then when turning the lights on manually, power will back feed into the camera and trigger it to turn on for as long as your lights are on. Your choice. But remember, doing that means no diode

 

Personally, I like being able to run the lights with the truck off. Since I have it trigger my backup camera, its hard to forget they are on. But if your worried about forgetting, then yes the part coming from the switch that says 12v battery fused can be connected to an acc source instead.

 

I use mine with the engine off all the time. You can still run the lights with the engine off, you just have to put the key in the ignition and turn to acc/on position.

 

Looks good, and I understand all of it somehow haha. What kind of fusing would I need, diode and relay type? Any specific gauge wiring to accomplish this? Can I tap into a 12v preexisting line with a fuse inline instead of running a separate line all the way to the battery?

Appreciate the great help!

 

Depends on the lights. I need to know their amperage draw in order to answer those questions. A 5amp diode should be plenty. Maybe 10amp. A fuse will be determined by your lights. Relay is a standard 5-pin automotive relay found at any auto parts store. Wire size is determined by lights as well, but 16g should be fine. If they are heavy duty lights with high current, maybe 14g. Need more info first. Your wire coming from relay pin #30 needs to go to the battery. The one coming from your switch can be taped into an existing 12v source. Unless you want to do the backup cam mod I explained, then it should also go to the battery.all the wires after pin #86 on the relay which go to the switch and the trigger etc, can be smaller wires like 18g. Everything else is what matters most.

 

Also note the orientation of the diode. The stripe needs to be facing towards the switch or relay (depending how you wire it) if you put the stripe on the side of the reverse signal, it won't work

 

They aren't much. Just guessing no more than probably a few watts each. Mind drawing up another diagram with what I need to get from the auto store to get this rolling? Your diagrams on spot on

 

Yeah I'm at Disneyland right now but I'll draw a good one either tonight late or tomorrow for you

 

I've attached a diagram that pretty much mimics yours, but am unsure of some things. Once the lights are put together, are they to be spliced in with the wire that goes to the switch? I'll update the led watts and such in just a minute for proper gauging and fuse sizes. Any specific relay or just the standard 5 pin?

 

The answer to your question in the diagram is no, those are not supposed to be spliced together. The fuse size for the signal going to the switch isn't really important just as long as it is fused. The power draw on that wire will be very low as it is only supplying the power necessar to operate the little magnet inside the relay. The other fuse size will be determined by how much power your lights draw.

I use a 4 pin automotive relay from radio shack for all my installs. It's the same as the one you posted, but doesn't have the extra terminal.

 

Subbing. To reread when I'm doing this.

 

as stated below, no that circled area is not spliced. The lights go directly to pin 87 and the switch goes directly to pin 86. No connection between those 2 wires. The wire after the switch can go to any accessory circuit. You can wire to the battery if you want to with a 2.5 or 5 amp fuse, or use an add-a-circuit with a 2.5 or 5amp fuse. You can tap off of the radio or cigarette lighter or ignition fuse. The main wire off pin 30 must go to the battery and will be fused according to the lights used. Most likely a 10amp but well see. The 4 pin relay will actually work better. Its the same thing its just missing pin 87a which isn't used anyways.

Correct.

 

Be sure each light is grounded individually and then all the positive wires are spliced together to go to the relay. See picture for details...

 

Can I use a higher diode with no repercussion? I've got a 4 pin relay, a 5 amp fuse for the switch and a 10 amp fuse for the battery. 16gauge wiring all around should work and I'll get started on this thing. Sound good?