1895 incand. bulb LED replacement NOT working!

[Paul Chet]

Hey gang,
This one is for our LED gurus ... I will first apologize as I have searched high and low here and not found my specific bulb type already discussed.

I ordered a bunch of LED replacement bulbs for my Play Pac running lights. The incandescents are old and with 14 of them, they will run out the battery in about an hour if, lets say you forget you left them on while testing them. Don't ask me how I know this.

I did order my LEDs from China and I am not concerned with anything other than If they work. I tested them right on the battery and they work perfectly. I put them in any of the Bargman fixtures and not a one of them works even if I rotate them 180 degrees (but the other incandescents continue to work) I read that might solve it as well as other polarity issues like switching the wires. Also see some discussion about special kits to add inline, and grounding, etc. But the discussions were more about poor glow or they weren't turning off. Mine don't even light up at all. I did try to hook them up to the terminals of the very first light that gets power from the TV wiring and noticed that if I did that, that all of the rest of the lights down range shut off. Any thoughts there?

I also read that they can be sensitive to true voltage and my Voltmeter says the full dose is coming from the TV. Guess I am wondering if anyone here, based on my symptoms, has a really quick and easy 5 minute fix!?

Likely not and I appreciate that, but i really want them to work. I guess i just want to know if someone might say "forget it and stick with the incandescents - your play pac is too old, etc." if that's the case, I need to get these bulbs back to China before my return window closes.

Thanks for any help.

[Orcus79]

Is this with any of the LEDs or just one? This may also be a case of buyer beware and you get what you pay for.

LEDs being "electronic" as opposed to a resistance load are more sensitive to voltage drop and clean contacts. have you tried to measure the voltage at the socket? Not being 100% sure on how your lights are wired, if you take one lamp do the rest go out or stay lit? Knowing that will tell you how they are wired.

Have you tries, for s***ts and giggles really, replacing everything with LEDs? Also compare the bases of your old lamps with the LEDs, it could also just be a matter a poor connection because the base and the socket are not mating correctly. Either from wear or slight difference in manufacturing.

[Wallo]

One thing I learned in my research is that some bulbs have offset nodules at the bottom of the bulb. Others have nodules that are not offset, but at 180 degrees from each other. I don't know if it occurs in the same type of bulb or not. But, I'm sure you would have noticed that difference

[Paul Chet]

Thanks Sean and Alice.
I hear ya ... but I have to say, I have had ONLY good experiences with all I have ever bought from China - with special regards to electronics. I have bought junk knowing its junk (iPhone /iPad covers and HDMI cables for a buck that work flawlessy, etc.) but the sensitive stuff has thus far always exceeded my expectations for the cost.

Plus, I tested the LED bulbs right at the battery and they lit up perfectly. I tested 15 of the 18 I bought in various sockets and I got nothing. I jiggled them ebery which way just to see if in fact there was some contact issue but not even a flicker. My running lights are wired so if one goes out, all of the others up or down range still stay lit. I tested voltage at the first socket where the power comes in and I had the 12 volts.
The base of each LED bulb is pretty much a mirror of the incandescents so I don't think there is any trick there. I am beginning to think, they are either too sensitive to any small drop in voltage or there might be some grounding issue?
Just for fun I will go ahead and try to replace every light as you mentioned with LEDs. Who knows, it might amuse the trailer wiring gods enough to cut me some slack.

Thanks again, and if anyone else can think of something not yet discussed, please do not hesitate to chime in.

[Thomas G.]

Can you verify with a multimeter that the the center contact in the fixture is positive and the base is negative? If it was inadvertently wired wrong the incandescent bulbs wouldn't care, whereas the LEDs would .

[Raz]

First, as Tom suggests check the polarity of the socket. If that's ok here are more things to look at.
-are you sure these are 12 v lamps?

-Do the bases match up exactly. With a bayonet base the little pins determine how far into the socket the base will go. Could the center contacts not be touching.

-Try holding some wire on the bulb contacts and make connection with the socket contacts.

-Try gently cleaning the base with contact cleaner and steel wool.

Let us know what you find. Raz

[Roger Kimble]

I hooked up LED's from China and had to switch the polarity, then they worked fine, like tom said.

[Paul Chet]

Once again, the beautiful minds here at Fiberglass RV have prevailed!!! In less than half a day, you fine folks have saved one slightly frazzled, know-nothing do it yourselfer from descending into total madness! A hearty thank you to Thomas G. for bringing to attention the salient point of reversed wiring. Sir, I wish I could send you a very cold beer through the aether! Likewise for Raz, Roger, and all those who took some time to help me troubleshoot this problem.

It was indeed reversed wiring - so I went to the wiring coming in off the trailer and simply tested one LED bulb there after checking Thomas' recommendation and sure enough, they worked. All I had to do was snip, switch, resolder, et viola ... my LEDs ALL lit up gloriously and no return shipping (on me) back to China! I really hate filling out those pesky customs forms.

It's funny, I have a lot left to do but was starting to question my sanity (not too difficult) and thinking I just couldn't get a break as seemingly (for me) no mod is too simple! When they lit up you would think I was Clark Griswold in Christmas Vacation!

Anyway a huge thanks to you all and I now have renewed momentum to carry on. The wood blocks are now fully fiberglassed (in the ceiling and floor - yuck what a mess that was!) and cured. Once I get that weight bearing column installed, I can really get down to finishing my rewiring and finally the finishing work. Good times. You guys rock!!!

[Thomas G.]

Originally Posted by Paul Chet

...... Sir, I wish I could send you a very cold beer through the ether! ........

Please fax it, I'm standing by.

[Paul Chet]

Transfer was going great until the smoke and sparks started flying! Will have to have to find a wet-dry Fax machine for these special transmissions! Thanks again all.

[Mike Magee]

This would be one of those "if you're ever in my neighborhood..." moments. Beer coming out of a fax machine sounds yucky anyway!

I have a question. If the wiring was reversed, why didn't it work to reverse the LEDs in the sockets? Would these sockets have some feature that prevents a bulb from making full contact in reverse orientation? Or is it something altogether different?

[Thomas G.]

Originally Posted by Mike Magee

This would be one of those "if you're ever in my neighborhood..." moments. Beer coming out of a fax machine sounds yucky anyway!

Well ya gotta have a refrigerated FAX machine - not made by Lucas.

I have a question. If the wiring was reversed, why didn't it work to reverse the LEDs in the sockets?

On a single filament bulb, the center nub in the base is positive and the brass base is negative. With a twin filament bulb (like a tail / brake light) both nubs are positive, and the base is the negative connection. Reversing the bulb in this case just changes which filament is brake light and which one is tail light. The polarity has not changed.

Would these sockets have some feature that prevents a bulb from making full contact in reverse orientation? Or is it something altogether different?

On a twin filament bulb the pegs on the side of the base are at different depths to force orientation. If you manhandle it you can force it in wrong. I think that you actually end up forcing even tighter contact on the base nubs. In any case, polarity is not affected.

[Paul Chet]

what Thomas said!
That few words of info about the base contact of the bulb needing to be positive was so much more useful than the couple of hours I did hopelessly searching the web. Just can't say how valuable this site is. I went out last night once it got dark to really see the LEDs at work and after that I don't think I even need to think any more about my porch light mod!

[Kenny Strong]

CHET

I bought a trailer to pull behind the Harley, one of the running lights did not work, somewhere in the past I read, it was critical for led lights to have correct polarity; I cut the wires and reversed them and it worked, I was going to send that, as a suggestion but I got here late. I still need more research on the wet or dry fax machine!

Later Kenny

[Mike Magee]

I get it now. Thanks!

[Paul Chet]

Kenny,
Yeah ... sometimes the most simple thing is the solution. Here I was ready to take the frame off and rebuild my truck in hopes that those darned LEDs would light up!

[Thomas G.]

Trouble shooting advice:

When you hear hoof beats, think horses not zebras.

[Wallo]

I cut the wires and reversed them and it worked

As one who is thinking of using LED's, does the wiring ALWAYS have to be reversed if changing to LED'S? Or is it the type of LED's that determine reversal?
Thanks,
Alice

[Thomas G.]

Originally Posted by Wallo

I cut the wires and reversed them and it worked

As one who is thinking of using LED's, does the wiring ALWAYS have to be reversed if changing to LED'S? Or is it the type of LED's that determine reversal?
Thanks,
Alice

You should not have to reverse the wires. Standard wiring practice is for the center connection on the bulb to be positive.

The issue above was caused by nonstandard wiring.

[Wallo]

Thanks for the clarification. Now it will be easy to change the bulbs without worry.