Odd Electrical Issue...pillar Lighting Voltage?

[luvmyglock]

So I am wiring in some LEDs near my pillars. I have never had b-pillar lights, so I thought I would use the wiring for them to install some LEDs. I replaced the door plunger switch that was broken and cleaned the other one up. Afterwards, I went and checked the voltage at the light end of the wire and found out that I am getting 7.5-8v constant. The issue here is that I am getting 12v in the morning or when it has been sitting for a while...The battery is good, and the truck is a daily driver with no battery or voltage issues. What would cause such a dramatic voltage fluctuation in this wire? Power is NOT intermittent, it's just a solid 8v after it's been on for a minute..then shut the doors, open them again, and 8v again! I can shut the doors, leave it, and come back in eight hours and get 12v...what's going on here?!?! :???: :???: :???:

[ftpiercecracker1]

Are you using existing wires? or did you have to run all your own wires? If the latter is the case where are you getting power from?

[luvmyglock]

I am using the existing wires, which are wired into the door "plunger" type switches for GROUND. (White/black for ground and red for constant 12v)

 

BTW I'm getting good continuity on these wires when testing.

[Eagle]

..what's going on here?!?! :???: :???: :???:

 

Heat.

 

The door post switch is in the ground side of the circuit. The courtesy lights are always hot, and the door post switch just closes the ground side of the circuit when the doors are opened. When wires and connections are cold, they conduct optimally. Heat increases resistance, and current flow generates heat. So ... my guess is that there's still a bad ground, or a bad connection somewhere in the circuit, and as the lights run for a couple of minutes that connection heats up and the resistance increases at that point, thus lowering the voltage.

 

:shrug: That's the best I can come up with on short notice.

[luvmyglock]

 

..what's going on here?!?! :???: :???: :???:

 

Heat.

 

The door post switch is in the ground side of the circuit. The courtesy lights are always hot, and the door post switch just closes the ground side of the circuit when the doors are opened. When wires and connections are cold, they conduct optimally. Heat increases resistance, and current flow generates heat. So ... my guess is that there's still a bad ground, or a bad connection somewhere in the circuit, and as the lights run for a couple of minutes that connection heats up and the resistance increases at that point, thus lowering the voltage.

 

:shrug: That's the best I can come up with on short notice.

Bingo. "Bad connection somewhere in the circuit" takes the win. I fee like an idiot, because where is the first place to check when something electrical is wrong? You got it..FUSE BOX! After all this shooting wires, cleaning grounds, rewiring stuff, and pulling my hair out I failed to check that the fuse was firmly seated...it wasn't. Pressing the fuse in with some force gives me 11.89 volts at the lights and BRIGHT LED lights. Now, for the pictures! LED lights drilled into the panels so that I don't have any ugly lights hanging off anything! They're green for night vision preservation purposes, not to be a ricer ;). I'm installing white in the middle of the other side, with green on the outsides.

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