The Stovebolt Site Forums The Shop Area The Electrical Bay LED Tail Light Questions

Last night a guy who was following me said my tail lights were really dim. I figure it doesn't matter if the intensity is "right"- what matters is what someone driving behind me sees.

First, I'm going to run a dedicated ground wire to each lamp. But I'm also seriously considering going to LED tail lights. Lots of questions:

- I'm running a 12V system with no turn signals, just tail/brake lights and the license plate light out back. (No change is planned for the license plate lamp.) Should I be looking for "dual intensity" 1157 replacements ?

- I know "more is better" when it comes to LED brightness, but what should be my minimum LED count/bulb requirement? There are lots out there. Heat generation isn't an issue, is it?

- In the "dual intensity" line, are the LEDs evenly divided between the two "filaments"? In other words, does a 36 LED product devote 18 LEDs to dim and 18 to bright?

- Would a square printed circuit board with a square pattern of LEDs look square-shaped, or would this pattern tend to blend circular over a distance?

- If I go with 24V 1157 dual intensity, then will the LEDs burn out twice as quickly, but be twice as bright as a 12V offset?

- 100° wide angle or narrow projection? Seems like narrow is all that I'd need, given the housing. Along the same lines, there isn't a need to add reflectivity to the back of the housing (such as white paint or aluminum foil) since the LEDs are so directional, right?

I guess that uses up my allotment of questions for August. Thanks for any help/advice you can offer.

Bill

Hello TxLaTx,
I can only offer a little experence I have had with LEDs. A LED is a Light Emitting Diode. There is no filament to burn out thats why (in my opinion) there so great. They will put out almost 100% more light than a filament style bulb. (seems hard to believe I know), run under water etc,etc,. They need no reflective surface either. The one thing I have found out though is that they need a good good ground. If they don't they will fail. (only happened to me once on an old trailer) I just put a set into my two ton and they are bright and sharp! I recomend them if your on the fence about it. While they aren't original they really work well. I don't claim to be an electrical master I just know what works for me! Hell, I came here to ask a question today....

24 volt LEDS will either not work at all on 12 volts or they will be very dim. Supplying less than the rated voltage of anything will always result in diminished performance. The dual intensity LEDs should have a diode and resistor in series with the taillight wire that reduces the current to all the LEDs and the brake light wire bypasses the resistor to give full current to the LEDs, but I haven't seen a schematic of the arrays to see if that is how they did it. If half the LEDs were dedicated to each function, the brake lights would not be bright enough in the daylight.

The 6V LEDs I use have the dual intensity LEDs in that they all light up on low and high intensity. Each LED gets brighter when I apply the brakes. Whether the bulbs you're looking at are that way is a question you need to direct at the folks selling them. My experience with most directional LEDs bulbs that I've seen on other vehicles is that they create a red "hot" spot in the center of the lens rather than lighting up the whole lens & housing as a regular bulb would. The other style in the link you posted (square 32 LED) would light up more of the lense. A downside would be you'll need to figure how to attach them to your lenses. I would think the wide angle would be better than the narrow. My 6V LEDs are shaped more like a regular bulb with 32 LEDs wrapped around the bulb so they're omni directional and light the whole inside of the housing thereby illuminating the whole lens.

Leds won;'t work with blue dots either, unless you modify them. Here's the Technostalgia kit that I'm running, w/blue dot mod.
http://rides.webshots.com/photo/2368955000092261295qrmCdN
http://rides.webshots.com/photo/2739260370092261295Qaohye
http://rides.webshots.com/photo/2752257200092261295eZVJHY

I put the LED's on my truck and I love 'em! They look great and, more importantly, they are safer!!

Check 'em out here - with links to purchase, too:
http://alanhorvath.com/54chevy/tailights.php

A couple of points from my experence with LED's. You will need to also replace the lens on your tail lights for them to do their job correctly. The new lens acts as a defuser to spread the directional visible output of the LED's. The guys above are correct...the LED guys place a diode in the circuit to reduce the voltage for tail lights and bypass it when braking as all the lamps 'burn' in both cases. No way will LED's look as orginials but as Alan says 'safety first'. They run very cool so heat will never be a problem. Pick up any street rod mag and you will find ads for them plus if your lucky someone makes your tail light lens set up for LED's.

see
http://www.aerostich.com/catalog/US/ElectroPods-p-16991.html

http://www.amazon.com/ElectroPods-Flashing-Motorcycle-Brake-Lights/dp/B000TK7ZJK
i have adapted three of these inside my original housing (s).
brake . stop . tail.
i also have two round marker LED's on my roll pan below the tail gate. tail and brake.

http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=10A.jpg

http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=587685-R1-036-16A.jpg

http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=587685-R1-030-13A.jpg

http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=587685-R1-034-15A.jpg

the turn signals are these:

http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=587685-R1-016-6A.jpg

http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=587685-R1-026-11A.jpg

hope this helps

Note: The LED's I bought have the lights *inside* the red lenses ... and they plug right in, too.

Thanks for the replies, guys. Being the impatient guy that I am, I went by the nearby AutoZone and picked up a pair of 1157 (red) 12 diode LEDs for $16. These are the direct mount style- they install just like replacing a burned out bulb. VERY easy!

After replacing the first bulb, I was stoked because the light was SO BRIGHT. But then I noticed some grounding problems with the other side. Long story short, I have VERY GOOD brightness on both sides at the moment, but no brake lights, only tail lights! I think my problem is that I'm 180° out of phase with the socket. I'm going to mess around with it this weekend and see if I can get it to behave. (I have dedicated grounding wires at each housing, going from the housing bolts to the bolts that hold my bumper to the frame, so I'm ruling out grounding.)

Assuming I can get the intensities to work, this has got to be the easiest, cheapest, and best safety improvement around. I'm pleased that it still looks mostly stock, unless you look through the lens really hard, and that it required nothing more than a twist-n-pull once the lens was removed. Knowing what I know now, I wish I would have done this as the first project on my truck.

If the 180° thing doesn't work, any suggestions on what else to check would be appreciated. The LEDs are 12v, dual intensity, so I believe I'm working with the right equipment, and I had brake and tail lights before the swap. I have no turn signals to factor into the equation.

Mucho appreciado!

Bill

HELP!

I'm scratching my head trying to figure this one out. Please offer any recommendation to solve this problem:

I have tail lights when the headlights are turned on. (Proves the light switch and lamps work.)

I have brake lights when I press in the brake pedal. (Proves the brake switch and lamps work.)

I DON'T have brake lights when I turn on the tail lights, at least not routinely. I did a check prior to a 10 mile drive and found all systems okay. After the drive, the brake lights only work when the headlights are turned off! One last point- I have dedicated ground wires from each housing to the frame.

Frustrations, frustrations...

Bill

Read my reply on how dual intensity LEDs work. If you have the brake and taillight wires reversed, you will never see the brake light when the taillights are on with LEDs. Are the brake lights somewhat dimmer than the taillights when each is used independently?

You stated that you did a check prior to a trip. DID your complete system check out as it should, including a brake light check with lights on? If so, then a problem has occured. If not, then 'Bsldy' sounds right on.

Use a piece of wire to determine which contacts on the bulb are the low & high contacts by holding the wire to each contact while touching the base to ground. Then use a test light to determine which socket contact is which. I suspect Baldy is correct about you being 180º out of phase on your wiring.

I had to laugh at myself, Baldy. I read what you previously posted, but I didn't really understand the "nuts and bolts" of what it meant. It took your second reply, as well as Beltfed's and Tiny's suggestions to get me to do the RIGHT thing and get the problem isolated and fixed.

Problem? The RIGHT SIDE ONLY was 180° off! Left side was okay. Instead of just messing around with a voltmeter, this time I pulled out a 12v power supply and a contact probe. I learned (and labeled) what each bulb contact did, and checked the contacts in the sockets. All said and done, I now have the cat's meow of tail lights!

Thanks to you all for your suggestions! Without them, I'd still be scratching my head.

Bill

or
YOU could do it yourself
see tech tip
http://www.stovebolt.com/techtips/led_light.html

I was considering leds a while back but I recall some where something about the turnsignals not working correctly...has that changed??? I like Alans approach but its a bit costly... My question now is I have 6volt system and use 1156 bulbs with turn signals front and back... Whats the best approach for me to convert to LED's and where do i get them Pls... thanks Peter

I got mine here. To make your turn signals work you'll need to wire an incandescent bulb into the circuit to provide the resistance the flasher needs. I think there is also a flasher available that will work without the extra bulb but I don't know where to get one.