Cigarette Outlet Fusing

AnOldUR

Our 2020 320S has a cigarette lighter type outlet in the back by the bed on the drivers side. While trying to find out what each of the 12V fuses provided protection for, I removed every fuse. None of the fuses cut power to that 12V cigarette outlet. Anyone know why or have an explanation?

edit to add: To see if there was power there, I plugged in a 12V device that had an LED pilot light on the plug. That light never went out. Could there be residual power keeping the light on even after the fuse is removed?

Freespirit

@AnOldUR there is a response from @Bayliss that solved my issue that appears to be what you are describing. His response is at the bottom of the discussion titled 

Fuse keeps burning out

Cheers

MuttonChops

@AnOldUR the referenced thread @Freespirit provided is a bit long.

The short version (pulled from the 'Fuse keeps burning out' thread) is your LED Pilot light is 'seeing' the available current used to light the Power Center 'Fuse Bad' LED.

AnOldUR

Thanks. Sounds similar to the household wall switches that glow when in the off position so that you can find them in the dark. So any load greater than a little led would not pass through the resistor? Makes sense. I'll give it a test under load to confirm it in my head.

JeffroNC

@AnOldUR that’s why I keep an old school incandescent 12v test light. It won’t glow on a high resistance circuit like the one above. It also provides a small load which helps me with diagnosis.

BrianZ

AnOldUR said:

So any load greater than a little led would not pass through the resistor? 

Not exactly, but, without the fuse in the circuit, the available current is limited by the circuit to something on the order of 10-15 milliamps.  That's enough current to light an LED.