Camper shell LEDs...electrical guys please help

is this too much watts for the light? the wire reads 12 volts when the light is disconnected (so just 12v running from the battery to the bed of the truck) then when i connect the ground and power to the new led light i measure the volts it only shows around 8v??? and is very dim. when i connect the positive and negative wires straight off the light to the battery it is very bright so the leds aren’t broken. WHAT COULD CAUSE THIS VOLTAGE DROP??? i also have 2 smaller led lights off the same circuit with the truck battery. (they are also pretty dim) someone please help i am frustrated i don’t know why these lights are dim.

also when i turn on the smaller led in the truck bed with the new led light on (very dim already) it fully turns off and voltage drops even more to around 5v??

how do people run 3 led strips at full power and i can’t even run 1 small led at full power i don’t get it everything is grounded at the frame behind my tail light and power is good up until it connects to lights then the voltage drops.

how can a 12v truck battery not run 3 led lights

also i checked my battery it should be healthy it’s like 12.7V with truck being off

 

I bet if you can expand on "the same circuit" mentioned above people will have suggestions. There is clearly a voltage drop in that circuit so I'd focus in getting 12v to that circuit or running new fused lines from the battery.

 

Have to follow the wires see if theres a break or something shorting out or not making good connection.

I had issues with my camper shell lights and 3rd brake light. The connectors werent seated right at the jumper off the fuse box, the butt splices were corroded, at rear of truck, they used painters tape in one spot under the electrical tape, wire was chafed through coming in at the bed truck...

I basically had to redo all the connections and changed plug on a 2 wire line.

 

Couple things it could be. First start by checking your ground. Did you run the growing all the way back to the battery? If so tie into a ground with the brake lights or clean ground on the frame. Usually this would be caused by a poor ground.

If the ground is ok, what gauge wiring are you running from the battery? Is it fused? What are you using for a fuse holder? Check the connections.

is this an old or new install? Around here there are tons of issues with corrosion. One small nick in the wire and salt and water get in there and the wire turns into green cheese. Or the wire turns black and oxidizes. You can check continuity of the wire. Put test leads on each end. You should have a low reading 2-4 ohms. Anything more and you have an issue with the wire.

 

by same circuit i mean all positive lines join into 1 wire and go to the battery then all negative lines join then ground to the frame.


where the left and right lights tie into. there used to be another light up here but i cut it out and put that new one in. all lights tie in up here then go to the trailer connector and to the battery^ also where the black electrical tape is near those blue connectors are is where i cut in the line to join my new light. it reads 12v when it’s just the wire but if i connect the lights wire positive and negative to it, it drops to 8^

light that came with the shell one is on the left one is on the right^

14 gauge wire running to the battery^

green and yellow are power and ground all 3 lights end up going to this yellow wire then to the battery^

also put a 15 fuse right before the battery on the positive line.

 

What size wire are you using? How long is the run? Is your "ground to frame" to a spot where something else was grounded or did you ground to some bolt on a frame?

The 1 wire you joined the others to, often it should be a larger wire to handle the potential extra draw. Also if you have a long run you might be getting line loss which causes voltage drop. The ground you are using should be a good ground and if Toyota put a ground there, it's probably a good spot to ground to. People often think to just back off a screw or bolt that's attached to metal and ground to that. That's may not be a "good" ground.

It's fairly common to hook stuff up, turn it on, and discover problems when you are actually drawing power.

 

hey man i updated the pictures it would be great if it helps in any way

 

updated pictures please feel free to give more input

 

Not knowing what the draw is on your LEDs I'm going to guesstimate you swap your 14ga power and ground to 10ga.

 

isn’t the draw on led the 7.4 watts?? it shows on the Amazon website

 

thanks for replying and giving me ideas man i appreciate it i been trying to fix this for like 2 weeks now

 

also what would making the wire bigger do? make less resistance for more power to flow?!

 

okay so you are suggesting after the trailer connector to switch to 10 gauge all the way to the battery.
the ground i put a self tapper in behind the tail light.
also i’m not sure what gauge the actual trailer 4 pin connector is, would it matter or can i switch gauge after the trailer connector wire ends?

 

i just ran the wire myself about 2 weeks ago, there is one connection under the truck that i put tape on, you think maybe water got in there?

 

If you ran 14g from the bed to the battery that's likely the problem and the 15a fuse will not pop before that wire.

I ran 6g welding wire from a breaker I installed next to the battery to a fuse panel in the bed and run my accessories off that. Overkill for just LED lights but 12ft of 14g is only rated for 10a. You need to figure out the draw of your lights and size the wire to provide more power than the lights draw.

 

okay sounds good would i have to increase the ground cable gauge aswell? (increase as in size like 10 gauge?) and how do you figure out the draw of led light power??

 

VxA=W
7.4Wx3=22.2W
22.2/12=1.9A

this is assuming that the stated wattage is correct per fixture

 

woops 7.8W, let's say 8 for simplicity
8W x 3 = 24W
24W / 12V = 2A

 

okay so can 24 watts not run off a 12 volt battery of a distance say 14 feet with 14 gauge? how can you figure this out. thanks man

 

14ga has an ampacity of 15 Amps with a 0.05V drop over 3 meters
I don't think it's your wire size if this is the only thing on the circuit
I'd look for bad connections
did you test the lights before putting them in
a multimeter to measure volts and amps would be useful