12V Wiring Help

  • HTML tutorial

Jason Shelby

Rank VII
Member
Investor

Creator III

5,660
Lexington, Henderson County, Tennessee, United States
First Name
Jason
Last Name
Shelby
Member #

6080

Service Branch
TN National Guard

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
I just want to be sure you're not running any in pairs. So just 3 light fixtures all totaled?
 

Jason Shelby

Rank VII
Member
Investor

Creator III

5,660
Lexington, Henderson County, Tennessee, United States
First Name
Jason
Last Name
Shelby
Member #

6080

Service Branch
TN National Guard
I just want to be sure you're not running any in pairs. So just 3 light fixtures all totaled?
Those above specs I posted a picture of are for a pair of lights, so 3 pairs total, at the tent switch, one pair per switch.
 

Attachments

MrRob

Rank II
Member

Contributor III

327
Austin, TX, USA
First Name
Robert
Last Name
Harvey
Member #

26403

One potential addition to Neal's diagram would be to use a single pole double throw (SPDT) switch with a center off position for the tent switch, with +12v wired to the center pin, the diodes+relays attached to one throw, and the +12v for the 3 trailer switches attached to the other throw.

This way when the tent switch is in the "up" position all the lights would go on. When it is in the "down" position the 3 trailer switches would control the lights. And in the center position the lights would be off regardless of the position of the trailer switches.

I was thinking the same. With the addition of a "master switch" at the trailer to switch between "nighttime safety mode" and individual light use.
Does that make sense Neal?? Also, would it work without creating ground loops or overpowering a part of the circuit?
[Just brainstorming... I haven't had my coffee to draw out the schematic yet]
 
  • Like
Reactions: Neal A. Tew

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
@Jean Klaude The Jeep

When we started this discussion I made two bad assumptions. The first was I thought you were speaking of larger more powerful lights. The second was I was assuming a ground tent some distance away. Both were stupid in hind sight and I'll blame it on a lack of coffee.

Looking at the KC info on their site, it looks like the wiring harness they include does NOT use relays. I'm confident it's because these little guys are of such little current draw and the wiring is short. (I also have some small LEDs on a trailer w/o relays.) It looks like the 1.6 amp is per light and not per pair yielding 3.2 amps per circuit.

What length of wire would you need to add to reach into your tent? Edit: Disregard

I have an idea for how to do it with minimal modification to the KC harness. Give me a bit to draw it up.
 

Jason Shelby

Rank VII
Member
Investor

Creator III

5,660
Lexington, Henderson County, Tennessee, United States
First Name
Jason
Last Name
Shelby
Member #

6080

Service Branch
TN National Guard
@Jean Klaude The Jeep

When we started this discussion I made two bad assumptions. The first was I thought you were speaking of larger more powerful lights. The second was I was assuming a ground tent some distance away. Both were stupid in hind sight and I'll blame it on a lack of coffee.

Looking at the KC info on their site, it looks like the wiring harness they include does NOT use relays. I'm confident it's because these little guys are of such little current draw and the wiring is short. (I also have some small LEDs on a trailer w/o relays.) It looks like the 1.6 amp is per light and not per pair yielding 3.2 amps per circuit.

What length of wire would you need to add to reach into your tent?
Those little KC lights put out a TON of light, especially in the backwoods of the Cherokee National Forest.

Tent is 6ft, switch will be a the opposite end from the trailer control panel, so 8ft probably, 10ft max.

I truly appreciate all the time you are putting into helping me with this. I’ll wire it however you tell me it will work.
 
  • Like
Reactions: Neal A. Tew

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
One potential addition to Neal's diagram would be to use a single pole double throw (SPDT) switch with a center off position for the tent switch, with +12v wired to the center pin, the diodes+relays attached to one throw, and the +12v for the 3 trailer switches attached to the other throw.

This way when the tent switch is in the "up" position all the lights would go on. When it is in the "down" position the 3 trailer switches would control the lights. And in the center position the lights would be off regardless of the position of the trailer switches.
If I understand the intent, the added benefit would be that you could go to bed with some lights on and turn them off in the tent. That's a great advantage I hadn't thought of. It just adds to the complexity and makes the diagram harder to draw. LOL

What do you think about it, @Jean Klaude The Jeep?
 

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
Here's where I'm at right now based on the valuable suggestions from @slomatt and @MrRob.

I did the switch a little differently so that the majority of the time the relays aren't energized. They are only activated at the need to override the trailer switches. I'm also trying to allow the use of the factory harnesses with as little modification as possible.

Also, you can use small wire and switch in the tent since the relays carry the combined load.

You guys double-check me on this.

added MASTER KILL.png
 
  • Like
Reactions: MrRob

Jason Shelby

Rank VII
Member
Investor

Creator III

5,660
Lexington, Henderson County, Tennessee, United States
First Name
Jason
Last Name
Shelby
Member #

6080

Service Branch
TN National Guard
One potential addition to Neal's diagram would be to use a single pole double throw (SPDT) switch with a center off position for the tent switch, with +12v wired to the center pin, the diodes+relays attached to one throw, and the +12v for the 3 trailer switches attached to the other throw.

This way when the tent switch is in the "up" position all the lights would go on. When it is in the "down" position the 3 trailer switches would control the lights. And in the center position the lights would be off regardless of the position of the trailer switches.
If I understand the intent, the added benefit would be that you could go to bed with some lights on and turn them off in the tent. That's a great advantage I hadn't thought of. It just adds to the complexity and makes the diagram harder to draw. LOL

What do you think about it, @Jean Klaude The Jeep?
Haven’t considered that, I was more focused on the bumps in night part. LOL
 

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
@Jean Klaude The Jeep
If you decide to try the last schematic and need any help with the components, etc, don't hesitate to let me know.
Some help with the diodes would be good, size and type, so I can look them up on Amazon.
Here's an inexpensive option below.

The stripe on the diode corresponds with the vertical line on the diode in the diagram.

Shorten the legs just long enough to put on red crimp terminals. Cover with heat shrink and you'll be all good.

 
  • Like
Reactions: Jason Shelby

slomatt

Rank V

Influencer I

1,723
Bay Area, CA
Here's where I'm at right now based on the valuable suggestions from @slomatt and @MrRob.
One concern with this setup is that the 2nd relay has to be energized for the trailer switches to be "off", which will result in power draw and could unintentionally drain the battery. I'm assuming the relays are there to protect the switch, but since the maximum draw for all 3 lights is only ~10A (3.2A x 3) a switch rated at 15A+ should be fine without relays.
 
  • Like
Reactions: Jason Shelby

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
Here's where I'm at right now based on the valuable suggestions from @slomatt and @MrRob.
One concern with this setup is that the 2nd relay has to be energized for the trailer switches to be "off", which will result in power draw and could unintentionally drain the battery. I'm assuming the relays are there to protect the switch, but since the maximum draw for all 3 lights is only ~10A (3.2A x 3) a switch rated at 15A+ should be fine without relays.
Yes, but as you say it's only energized when overriding the trailer. That only happens when he goes to bed with a trailer light on and turns it off from inside.

I can only see that being a problem if he forgets to turn it off on the way out of the tent in the morning and then doesn't notice the trailer light switch is on. If he then went home and parked it for several days in that position it could be an issue.

@Jean Klaude The Jeep , do you plan to use the lights during normal camp activities or just special occasions? If the latter, you might forgo the override to reduce the complexity.
 
  • Like
Reactions: Jason Shelby

Flipper

Rank V
Launch Member

Member III

2,865
Florida
First Name
John
Last Name
F
Member #

5021

Here's where I'm at right now based on the valuable suggestions from @slomatt and @MrRob.

I did the switch a little differently so that the majority of the time the relays aren't energized. They are only activated at the need to override the trailer switches. I'm also trying to allow the use of the factory harnesses with as little modification as possible.

Also, you can use small wire and switch in the tent since the relays carry the combined load.

You guys double-check me on this.
The diodes would not be needed, because in the middle position of the switch the bottom relay will still energize the circuit but even it feeds back in to the override relay or top relay the NO pin will be open or not energized so it dosent matter. With your design there should be a diode on the NC pin of the bottom relay of the bottom relay to match the top design or you create the same loop if one or more of the trailer switches are on and the override relay was on that also wouldn’t matter. Good design you just don’t need the diodes.
View attachment 182903
 
  • Like
Reactions: M Rose

BensonSTW

Rank III

Enthusiast III

I know I’m probably way late, but...It could be done without diodes. You just needed 3 relays. I got excited about the problem and drew the diagram before I realized this was a month old. Maybe somebody else can use it.E4DECA11-5312-492F-9C5A-4799AFFBDC7D.jpeg
 
  • Like
Reactions: Neal A. Tew

Neal A. Tew

US Rocky Mountain Local Expert
Mod Team
Member
Member

Member III

3,817
Pueblo West, CO
First Name
Neal
Last Name
Tew
Member #

12384

Ham/GMRS Callsign
N1TEW
I know I’m probably way late, but...It could be done without diodes. You just needed 3 relays. I got excited about the problem and drew the diagram before I realized this was a month old. Maybe somebody else can use it.View attachment 187626
Yes, that should work fine if you don't want the tent switch to override the trailer switches.