Having a hard time with this one

[suprz]

I'm installing under counter 12volt LEDs in my camper. The kitchen ones went great... BUT in the bathroom, I am getting confused. There is a single unlighted switch that I wanted to tap into... The problem is that there are 2 wires going to the switch... One loops around with a connector that plugs into the switch, but does not end at the switch, and the other terminates at the switch. I have confirmed that the switch that ends at the switch is a ground because if I tap into that one with the black wire from the LEDs and the other wire to the red from the LEDs, the LEDs light and from what I know is LEDs need correct polarity to work... Now here is what's messing me up, IF the switch I'm tapping into is off the LEDs work, but if the switch is on, the LEDs do not work but the light that is hooked to that switch works normally... I have tapped into both sides of the wire that loops around with the same results... What am I missing. I'm not bothering giving the colors of the wire cause we all know rv makers don't follow color codes

[wnjj]

suprz wrote:
I'm installing under counter 12volt LEDs in my camper. The kitchen ones went great... BUT in the bathroom, I am getting confused. There is a single unlighted switch that I wanted to tap into... The problem is that there are 2 wires going to the switch... One loops around with a connector that plugs into the switch, but does not end at the switch, and the other terminates at the switch. I have confirmed that the switch that ends at the switch is a ground because if I tap into that one with the black wire from the LEDs and the other wire to the red from the LEDs, the LEDs light and from what I know is LEDs need correct polarity to work... Now here is what's messing me up, IF the switch I'm tapping into is off the LEDs work, but if the switch is on, the LEDs do not work but the light that is hooked to that switch works normally... I have tapped into both sides of the wire that loops around with the same results... What am I missing. I'm not bothering giving the colors of the wire cause we all know rv makers don't follow color codes

Based upon what you’re describing here is my analysis:

The wire that ends at the switch comes from the light fixture and the other side of that fixture is grounded elsewhere. The “looped” wire comes from a 12V fused source. When you connect the LED across the switch, it’s grounding through the unlit light bulb. When you turn on the switch, the wire that ends at the switch is at 12V. It’s no longer at ground.

You need to hook the red LED wire to the one with the one that ends at the switch and the black to a ground connection somewhere else.