LED running lights reversed polarity don't work?

I bought some small LED bulbs to replace the running lights and yellow side turn signals on my 2005 17'

They don't work when plugged in, but If I run a small lead to switch the polarity they do work.

Turns out either my bulbs are wired with reverse polarity, or the camper is. Has anyone else had this problem?

I'll probably just stick with incandescent for these, but I'm curious if there's an easy fix.

The main brake lights work fine with LED bulbs.

Montana, can you turn the bulbs so that the pins on them go into the opposite ends of the sockets? This should correct the polarity problem. If not, you could simply take the light housing off the trailer and reverse the wire connections.

LEDs ARE polarized, and unless they contain circuitry to correct a reverse polarity, they won't work if the current tries to flow in the wrong direction.

- Jack

Montana, Did the same thing a couple of years ago. Never changed the bulbs, still have them. But I'm wondering if it's worth the time to reverse all those fixtures. Not much voltage loss driving down the highway.
Tree

Treeclimber said:

Montana, Did the same thing a couple of years ago. Never changed the bulbs, still have them. But I'm wondering if it's worth the time to reverse all those fixtures. Not much voltage loss driving down the highway.
Tree

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Right! And they're possibly on only at night too. Mine are not on during the day, even though I had my truck modified to have Daytime Running Lights.

- Jack

My feelings exactly. I spent a little while seeing if I could trace the wires back to one spot and switch the polarity at the source, but figured I'd do more harm than good and just decided to live with it.

I'm not too worried about the power saving. I just like the look of the bright LEDs and I really like how long they tend to last.

I might yet pull the fixtures off and flip the wires, but I'm not holding my breath.

I don't think you'd want to change the polarity of the entire circuit, because that would flip the polarity of the (non-braking) taillights too. They MAY be wired internally to be non-polarized, but I wouldn't do it without testing them.

I think you should check the running light bulbs. It's possible that if only one of them is inserted "flipped", it would cause the whole bunch to be dead.

If you have a bit of wire (to use as a jumper), you could determine which is the positive and negative pins on the bulb by trying to light one directly off your car battery. I've done this to test an LED that I thought might be faulty.

Another approach: Put all the incandescent bulbs back in. Then, one at a time, testing as you go, replace each with an LED. Flip the bulb if it doesn't light.

- Jack