LED Mystery

[Lin]

I bought a dozen LED bulbs to replace the single filament bayonet incandescent ones in my standard 12v RV fixtures.  When I installed them, some of the fixtures worked fine, while others did not light the LED bulbs.  They did work again with the incandescent bulbs though.  Why would these fixtures not work with the LED bulbs?

[Tim Strommen]

Might be wired backwards - remember, filament bulbs are essentially a polarity insensitive resistor - diodes only work one way.

If that isn't it, then try the LEDs that didn't work in a fixture that worked with the LEDs, you might have just gotten bad ones (it does happen with poor quality control).

Best,

-Tim

[Lin]

Yes, reversed polarity was the issue.  Thanks