"Polarity reverse" an explanation:
Some are talking about their LEDs don't work because the polarity somehow is reversed. This cannot happen except in one situation below. What is LIKELY is that it lost ground, or poor contact in the socket, or the flasher has a problem.
Of course the chinese LED could be made incorrectly LOL
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ACTUAL polarity reversal. There IS one situation where polarity on an LED can be reversed, causing no light
This is on the cars (I don't think any A bodies!!!) that had the flashing side marker lights, here is how they work
Those lights are a single filament small bulb, connected with one lead to the parking lamp circuit, and the other lead to the turn signal circuit on whichever side they are on
A...With both park and signal off, the marker does not light
B...With only park lamps on, the marker gets power on one lead from the park circuit, and the unlit signal lamp filament/ bulb ACTS AS A GROUND for the marker
C...With park lamps OFF and when signaling, the OTHER lead of the marker gets flashing power from the signal circuit, and the unlit filament of the park lamps ACTS AS A GROUND
THE MARKER between "B" and "C" is reversed polarity between the two situations. Trying to use an LED in that situation will only work in one case not both
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D....With park lamps lit, and when signaling, we now have a DIFFERENT situation. When the signal lamps are dark, the marker gets power from the park circuit and lights with ground through the signal bulb as before, BUT WHEN the signal lamp comes on, NOW WE HAVE 12V on both wires of the marker. The marker goes OUT then, when the signal lamp is ON. This then is the reverse situation compared to situation "C" above, where the marker and signal both light up simultaneously