Camper shell LEDs...electrical guys please help

another thing my led light seems like it’s 18 gauge positive and negative coming off the light, which is very small no? would it still be a voltage drop if i ran 10 gauge back to the battery but the wires off the light are 18 gauge?

 

yes man i checked everything. coming out of the trailer plug is 12.?v into the truck bed. so the wiring under the truck should be good no? the open wire where i would connect it to the light still would read 12v but as soon as i twist the wires of the led light together with the hot wire (12v) then check the volts again it is only 8v. you think maybe the wire off the led is too small?

see the wires are very small

 

drop of 1/3 of the voltage just hooking the fixture up, sounds like a bad fixture to me
do you know how to measure amps, I would expect the draw to be high with that much drop
you need to put the meter inline with the circuit to measure amps, at the ground point might be easiest

 

no idea how to measure amps i can prob watch video, can you do it with a multimeter?
also i tried one of the other led lights (Amazon led kit came with 4 lights) and got the same thing, very dim light same volt drop, so i don’t think it’s a bad fixture i’m so confused man

 

Yes, a multimeter should read amps
I'm leaning to damage wire
it only take a few strands of the wire to read 12V with no load on it but once the lights are hooked up and the lights are pulling amps any partial brake or bad connection will heat up and restrict the flow of power much like the dash light dimmer does

 

Had to read all that twice
If the lights work fine hooked directly to the battery, like you stated, then the problem is in the wiring. 14ga wire should be sufficient to run those LED lights. Taped connections can easily cause problems, use crimped connectors that you can heat up to seal them. Some even have low temperature solder in them along with the adhesive. I don't like to use remote ground points so to avoid trouble I run the ground back to the battery negative post.

I would start with two new wires, and run the power and ground back to the lights from the battery. No need to properly install it just run it along side of the truck for a quick test.

 

okay thanks for ideas, yes i soldered all joint spots and just taped them up, there is one spot under the truck that is a connection so maybe water got kicked in up there. so you are suggesting run the negative straight to the battery see if that works. if it doesn’t work then should i re do all connections where i soldered and put heat shrink and crimp connections instead of just solder and electrical tape??