Scare Light

[denverpilot]

Originally Posted by Desert185

All that is understood, but does not explain how 12v bulbs are OK in the TV, but 12-28v is required in the trailer.

Oh I've never read that as being the difference.

All of the warnings I've seen around here about not buying "12V rated" stuff from cheap sources seemed to indicate that the poster has reason to believe that the device is MAX rated at 12VDC, which is rarely true about any LED.

I suspect the TV vs trailer thing is just fluff added on which makes no electrical sense but was based on some misunderstanding of component ratings and DC systems. There's nothing particularly special about trailer 12V systems vs the TV's 12V system other than the TV system is often subjected to huge voyage spikes during engine start or electric motor cycling.

If one digs up the actual data sheets for these LEDs, most have a curve printed in them for lifespan and heat dissipation at a range of voltages. Some might be "on the downside" of that curve for lifespan and upside of heat created at the diode joint, meaning essentially that they're going to die sooner than a part that's rated to operate on up to 28VDC that's happily running in the middle of the curve. And simply not mounting them to a heat sink substrate surface correctly can easily kill many of them, too. Only the data sheet knows if it was done right.

(Check out some of the videos of people playing with 100W LEDs and the size of the heat sink sometime! Real 100W, not "100W light bulb equivalent" which is a goofy measurement, almost meaningless, that is used in household LED replacement bulbs for example).

Of course in a $4 for 10 part, finding the actual LED part number, the data sheet, and whether or not the things were built with "doesn't meet spec" parts and all of that is nearly impossible. But at that price they're throwaway if they die.

At higher prices, one might expect a good warranty which might be an indication of better design and quality, or it might just be someone rolling the dice and using the extra few bucks to handle the stream of returned dead ones. Heh.

I'm willing to risk a $0.20 part failure, maybe even more than one, for as simple as these are to replace. But if they blow out like candles in the wind, I'll assume the manufacturer either didn't read the datasheet and implement them correctly, or just doesn't care, and move on to another brand name.

Remember also that LEDs also dim over their lifespan, so even if they stay working, if they're driven hard, they eventually won't put out as much light as they once did. That's why I always chucked at early marketing that said LED home lightbulbs were going to "last 100 years!" Uh huh. Sure. Haha. You won't be able to see across the room, but it'll still be working. Ok. Ha.

Lots of problems in LED marketing and fluff. But they're so cheap these days, I'll just try a few if the first ones don't work out.

I remember when my first blue LED cost $2 just to hook it up to power supply and a current limiting resistor on the workbench just to see one in person... Heh. It's still around here in the junk drawer somewhere... Never decided to wire it permanently into anything. Of course now they're a dime a dozen. :-)

Maybe the folks warning about TV vs trailer LEDs can articulate what they're thinking is going to be an actual electrical problem with them. I don't see one. Just cheap LEDs on cheap mountings that might get too hot or be running at limits, but so cheap they're essentially throwaway. ????

[JRTJH]

I don't think there's any "significant" difference between LED's used in tow vehicles and in RV's. The "rub" as I see it is 12 VDC LED's in any automotive or RV application. There are a number of "12 volt DC LED's available that will work "perfectly" in low voltage lighting (around the house, etc) but will flicker or overheat in any automotive application (for the reasons stated in previous responses).

When an LED is used in a "constant voltage" application such as in a 12 VDC landscape lighting system, it's never subject to the "charge voltage" that's found in both a tow vehicle or in an RV. As stated, our charging systems operate at somewhere around 13.8 VDC and in some automotive applications, up to 16 volts (at times). That voltage "shouldn't" cause any problems for "quality LED's" but when buying a package of 10 LED assemblies for $8, some of the "diodes" on the board are probably not going to be able to carry the increased voltage without flickering or overheating.

So, I've found through my own experiences that LED assemblies that are "single voltage components" marked for 12 VDC (without voltage regulators) often don't last very long in either automotive or in RV use, while those marked for 12-28 VDC (with voltage regulators) seem to be more reliable.

I've don't recall any differentiation of LED's between tow vehicle use and RV use, but I've often recommended not using LED's that are rated "12 VDC only" in RV's or tow vehicles. They are OK in landscape lighting, but won't work well for our purposes.

So, if my previous posts over the years have led to the confusion between "automotive use and RV use" that's not what I intended. Both tow vehicle and RV are "pretty much the same environment" when it comes to LED's.

[denverpilot]

Some poor quality night photos. Looks like the scare light is going to work just fine.

Last photo is awful but it's mainly to show the slight color difference between the incandescent marker lights on the truck and the top markers on the trailer. Not quite "Amber" with the slightly blue/white light of the LEDs behind the trailer marker covers.

[Desert185]

Originally Posted by JRTJH

I don't think there's any "significant" difference between LED's used in tow vehicles and in RV's. The "rub" as I see it is 12 VDC LED's in any automotive or RV application. There are a number of "12 volt DC LED's available that will work "perfectly" in low voltage lighting (around the house, etc) but will flicker or overheat in any automotive application (for the reasons stated in previous responses).

When an LED is used in a "constant voltage" application such as in a 12 VDC landscape lighting system, it's never subject to the "charge voltage" that's found in both a tow vehicle or in an RV. As stated, our charging systems operate at somewhere around 13.8 VDC and in some automotive applications, up to 16 volts (at times). That voltage "shouldn't" cause any problems for "quality LED's" but when buying a package of 10 LED assemblies for $8, some of the "diodes" on the board are probably not going to be able to carry the increased voltage without flickering or overheating.

So, I've found through my own experiences that LED assemblies that are "single voltage components" marked for 12 VDC (without voltage regulators) often don't last very long in either automotive or in RV use, while those marked for 12-28 VDC (with voltage regulators) seem to be more reliable.

I've don't recall any differentiation of LED's between tow vehicle use and RV use, but I've often recommended not using LED's that are rated "12 VDC only" in RV's or tow vehicles. They are OK in landscape lighting, but won't work well for our purposes.

So, if my previous posts over the years have led to the confusion between "automotive use and RV use" that's not what I intended. Both tow vehicle and RV are "pretty much the same environment" when it comes to LED's.

It has been mentioned to use "regulated" bulbs, i.e. 12-28v in the trailer vs the straight 12v bulbs, but when you buy a bulb in the automotive section they are straight 12v. I agree the voltage is the same, but it is intimated that the trailer converter voltage is such that the unregulated voltage will reduce the LED bulb longevity. I see now that is bunk and agrees with my knowledge of automotive electricity, battery voltages and charging voltages.

[denverpilot]

Originally Posted by Desert185

It has been mentioned to use "regulated" bulbs, i.e. 12-28v in the trailer vs the straight 12v bulbs, but when you buy a bulb in the automotive section they are straight 12v. I agree the voltage is the same, but it is intimated that the trailer converter voltage is such that the unregulated voltage will reduce the LED bulb longevity. I see now that is bunk and agrees with my knowledge of automotive electricity, battery voltages and charging voltages.

I suspect that there are definitely SOME "bulb" arrangements made up of dodgy LEDs that aren't going to last very long above 12VDC, for sure.

Mostly what I cringe at personally is the ads that show so many LEDs crammed onto a circuit board that has no possible way to dissipate heat under each one, that the individual LEDs will constantly be over the temp range recommended by the manufacturer.

Usually though, I see this in flashlights attempting to be cheap knockoffs of really expensive flashlights with massive heat sinks that can light up whole city blocks.

Hey this "LED madness" has really taken hold on me here lately though, and most of these products now are amazing and really cheap.

I also grabbed two backup lights that would fit either the Yukon or the Dodge and decided the Yukon was the test bed tonight. Check out the color and brightness difference between the blue/white of the LED and the original backup light! (Also can see it in the ouddle light under the mirrors versus the backup lights... In the last shot from the second story deck. Also note how they're lighting up the side of the fiver... Wow. I like.)

[denverpilot]

PS: No vehicles were left sitting unattended in reverse and no animals, including silverback gorillas or Disney alligators, were harmed in the making of these photos.

(The Yukon uses the backup lights as area lights when you remote unlock it, which is why I chose it for the test. I could walk away and see just how bright these things really are...)

Now I want all the interior lights on the trucks done... Haha. This is getting fun at these low prices... :-)

[denverpilot]

Well THAT was interesting.

LED 2057 bulb replacement combination tail/brake lights came in for the trailer today.

Plugged one in, all looked well. Looked great in fact. Plugged the second one in, both come on. The truck lights are NOT on at this point. Hmm.

They're in "dim" mode. Taillight mode. Not Brake light mode.

I decide to try the hazards plus tail lights/markers.

Turn on both, markers start flashing on the entire trailer in time with brake lights. LEDs are working fine in hazard plus tail mode but all the markers are flashing with them. Interesting.

Decide to try a regular turn signal with markers on.

Left or right the LED on that side is brighter both for taillight and also flashing with the turn signals, as are all the marker lights again.

Put one regular bulb back in. All behaves normal. LED works. Incandescent on the other side works. Looks good. Swap LEDs. Same.

I ended up taking them out and putting the incandescents back. Something ain't right here. If two LED bulbs in the tail/brake position make the markers blink on and off, they did something wrong with the polarity circuit for the LEDs. It's breaking the ground connection for the markers when the brake lights flash.

Probably just return them for free to Amazon. Troubleshooting that makes my brain hurt, because obviously there's some current leakage from the truck when nothing is on, or they wouldn't light up in taillight mode when there's no lights active on the truck.

I could chalk that one up to needing load resistors perhaps, but the flasher didn't "hyperflash".

Now that I think about it... I iwonder if someone replaced the mechanical flasher with an electronic one on this truck and it's designed wrong...

I'll have to look tomorrow. Otherwise these LED bulb replacements are going back.

[denverpilot]

I'll be darned...

Had to do some work on the light switches for the map lights in the '01 Dodge 3500 DRW truck and noticed the LEDs I got for the trailer marker lights work well in the map and dome lights.



Yay LEDs.

[Desert185]

I'll try that, thanks.

Left the porch light on all night when a friend's sone stayed in the trailer. Now the porch light doesn't work. Nomtime to troubleshoot, but I hope its not the bulb after one night of it on.

[denverpilot]

Originally Posted by Desert185

I'll try that, thanks.



Left the porch light on all night when a friend's sone stayed in the trailer. Now the porch light doesn't work. Nomtime to troubleshoot, but I hope its not the bulb after one night of it on.

My porch light bulb only lasted two seasons set most of the time in the OFF position. Haha. And what little it was on, it was in motion sensor mode. Maybe ten nights total, tops.

But you also saw the UV damage to the plastic making it brittle (I assume) and then wind cracking damage to it, in he photos above...