I replaced my cluster gauge bulbs with led's early this summer and 3 of them are already burnt out ! Is this normal . ? Geez for the money these things should have lasted a little longer than a couple of months .
Anyone else experiencing this ?
69 mach 1
__________________
1969 Mach 1 , with American Eagle's 15"x8" 4.25 back space 235/60/R15 BF Goodrich tires
351W Massaged just a little with a mild cam and Edelbrock intake. Holly 650
1968 GMC step side short box
1967 Triumph 650 Tigar Twin Cycle
2007 Mustang
As Red Green Would Say. If It Ain't Broke , your not trying hard enough
Never givfe up the ship!
I can't really offer help, but I do know that LEDs should last almost indefinitely. They should easily last several times as long as a traditional bulb. Not sure what would make them burn out though
__________________
1968 C code Coupe "Tillie", stock 289 w/ 3 speed.
Desert car from Southern California. Rebuilding front
suspension, steering, and brakes before I add more
horses under the hood.
I replaced my cluster gauge bulbs with led's early this summer and 3 of them are already burnt out ! Is this normal . ? Geez for the money these things should have lasted a little longer than a couple of months .
Anyone else experiencing this ?
69 mach 1
Since I design LED lighting for a living, I will tell you what is wrong with retrofit LED bulbs. Time to get on my soap box!
Thermal Managemnet and low quality LEDs
The filament in a 60w incandescent bulb will run at 2000 to 2500 deg c. Dash lights may not run as hot, but an incandescet bulb produces light by heating up a tungsten wire. So heat or thermal management is not an issue with standard bulbs.
LEDs on the other hand are very sensitive to temperature. The life expectancy and light output is directly proportional to the temperature of the LED. General rule is for every 10c rise in temp, will reduce the life time by 50%. Most quality LEDs are guaranteed for 50k hours at a specific temp, generally 85c. If you increase the temp to 95c, then the lifetime is cut to 25k hours. Now if it gets really hot, you can see how the lifetime can take a real nose dive.
Retrofit Issues
I bought a set of LED dash lights for my 67, have to drink my own cool-aid sometimes. The blue high beam light went out after a few weeks. so far the whites are still working. However, the quality of the LED assembly is not good.
You would never see one of these in a tier 1 auto supplier.
Most of these so called automotive replacement bulbs use multiple LEDs. First to spread out the light and second, more LEDs = more light
Because they use low quality, low efficiency LED, they have to use many LEDs. Why do they do this? Because the LEDs are real cheap and put out little light. I work with single LEDs that are as bright as a Mag Light. 150lm from one LED.
The other issue is thermal management or heat transfer. A proper LED design has the LED connected to a heat sink. Remember, the cooler the LED runs, the longer it will last. When you try to stuff 5 or 6 small LED in a tiny bulb socket, there is no way to dissipate the heat from the LEDs. If you look at these dash bulbs, you will see that they are clustered on top of the bulb base. No thermal connection to the bulb base. Plus once you pop the bulb into the socket and add the lens, you have sealed off the LED from any air circulation. Like locking yourself in a closet with a space heater!. So you can just imagine why these get so hot.
The same goes for the LED replacement tail light bulbs.
In modern cars with LED back lit instrument panels, the LEDs are SMT (surface mounted) to a circuit board, this board is designed to dissipate the heat generated by the LED. LED tall light assemblies are usually on a aluminum board. These run very cool. Thus the LED will usually last the life of the vehicle.
The mark up on these retrofit bulbs are enormous. The cost of the LEDs for an instrument light are less than $0.50. After that all you have is a tiny circuit board, diode and bulb base. They are all made in China so the cost of the assembly is real low.
I have been looking at going to sequential LED tail lights for my car, but I am not impressed with the LEDs that are available. I hope to over the winter, design my own sequential tail light using automotive grade LED and LED drivers.
I certainly can't add more to the above, that was good info. I seem to remember when I did mine there was a + and - to them. Could you have some backwards?
__________________
1969 Coupe Restomod...in progress http://www.1969stang.com/mustang/for...ead.php?t=8156
2001 Bullitt
2008 Power Wheels Mustang Bullitt Conversion!
Past Mustangs: '66 Coupe, '69 Coupe, '69 Grande
Are you sure they're burnt out? I installed these bulbs recently in my 70 Mach and found that many of the contacts inside the original bulb sockets were old & brittle, therefore not making good contact with the printed circuit board. Try replacing the bulb sockets, Napa part #LS6500.
I also ended up replacing my PCB...
__________________
~Jeff
'70 Mach
Last edited by classicmach1; 08-27-2012 at 12:34 PM.
Reason: added info
They do say: "LED bulbs, if used inside the instrument cluster come with a full lifetime burnout warranty."
Guess I'll let you know how they work.
I did not mean to say that they would not work or even have reasonable life time. When you add it up, how many hours are the dash lights really on?
From what I have seen in the LED industry, the quality and life of retrofits, auto or home, are all over the map.
I went with the LEDs hoping that that they would be brighter than incandescent, they were not. And second that they would not melt the colored lenses on the instrument light. See attached pic.
Life time warranty is good, but I have never found it any fun to pull the cluster just to change a light.
a electronic technician at the local truck stop cb radio shop has USED led truck tail lights and clearence lights for sale. they are half the cost of new ones. soem of the brands are grote, truck-lite, etc. he said when he took out the trash he saw one in the trash bin. he decided to cut it apart to see why it failed. he said the resistors were burnt and looked to small. he installed larger watt resistors and the light worked again. everyday he checks the trash bin for led lights and puts new larger watt resistors in and said he has sold a lot of used lights. i bought peterson brand piranha led lights for my trailer and pickup truck, they have a 100,000 hgour garuntee !
a electronic technician at the local truck stop cb radio shop has USED led truck tail lights and clearence lights for sale. they are half the cost of new ones. soem of the brands are grote, truck-lite, etc. he said when he took out the trash he saw one in the trash bin. he decided to cut it apart to see why it failed. he said the resistors were burnt and looked to small. he installed larger watt resistors and the light worked again. everyday he checks the trash bin for led lights and puts new larger watt resistors in and said he has sold a lot of used lights. i bought peterson brand piranha led lights for my trailer and pickup truck, they have a 100,000 hgour garuntee !
Yea Shifter, I see that quite a bit with those lights. It amazes me what they will do to save a penny. In large volumes, a 1/4 to 1/2 watt resistor is just a few pennys. If the load is 1/4W then they use a 1/4W. No margin for safety.
My favorite saying "When someones wants a low price/ high quality part, they really want a low price part"
Since I design LED lighting for a living, I will tell you what is wrong with retrofit LED bulbs. Time to get on my soap box!
Thermal Managemnet and low quality LEDs
The filament in a 60w incandescent bulb will run at 2000 to 2500 deg c. Dash lights may not run as hot, but an incandescet bulb produces light by heating up a tungsten wire. So heat or thermal management is not an issue with standard bulbs.
LEDs on the other hand are very sensitive to temperature. The life expectancy and light output is directly proportional to the temperature of the LED. General rule is for every 10c rise in temp, will reduce the life time by 50%. Most quality LEDs are guaranteed for 50k hours at a specific temp, generally 85c. If you increase the temp to 95c, then the lifetime is cut to 25k hours. Now if it gets really hot, you can see how the lifetime can take a real nose dive.
Retrofit Issues
I bought a set of LED dash lights for my 67, have to drink my own cool-aid sometimes. The blue high beam light went out after a few weeks. so far the whites are still working. However, the quality of the LED assembly is not good.
You would never see one of these in a tier 1 auto supplier.
Most of these so called automotive replacement bulbs use multiple LEDs. First to spread out the light and second, more LEDs = more light
Because they use low quality, low efficiency LED, they have to use many LEDs. Why do they do this? Because the LEDs are real cheap and put out little light. I work with single LEDs that are as bright as a Mag Light. 150lm from one LED.
The other issue is thermal management or heat transfer. A proper LED design has the LED connected to a heat sink. Remember, the cooler the LED runs, the longer it will last. When you try to stuff 5 or 6 small LED in a tiny bulb socket, there is no way to dissipate the heat from the LEDs. If you look at these dash bulbs, you will see that they are clustered on top of the bulb base. No thermal connection to the bulb base. Plus once you pop the bulb into the socket and add the lens, you have sealed off the LED from any air circulation. Like locking yourself in a closet with a space heater!. So you can just imagine why these get so hot.
The same goes for the LED replacement tail light bulbs.
In modern cars with LED back lit instrument panels, the LEDs are SMT (surface mounted) to a circuit board, this board is designed to dissipate the heat generated by the LED. LED tall light assemblies are usually on a aluminum board. These run very cool. Thus the LED will usually last the life of the vehicle.
The mark up on these retrofit bulbs are enormous. The cost of the LEDs for an instrument light are less than $0.50. After that all you have is a tiny circuit board, diode and bulb base. They are all made in China so the cost of the assembly is real low.
I have been looking at going to sequential LED tail lights for my car, but I am not impressed with the LEDs that are available. I hope to over the winter, design my own sequential tail light using automotive grade LED and LED drivers.
I bought them for my '95. Had two clusters die within 6 months. Thankfully I bought two spares. When they burn out again, going back incandescent.
__________________
1995 GT convertible - Laser Red
1995 GT convertible - Black (Son's ride)
1966 GT Fastback under restoration- Code T Red
with White LeMans stripes.
if you can sloder you can make your own instrument lights. get the superbright leds and use 1 1/8th watt resisitor for each. auto meter sells an led dimmer. if you have aftermaket gauges use the base from the incandesent bulb.
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LED dash gauge bulbs
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