The headlights on my 88 Jeep are dim, they look amber. is this due to their age or low voltage?
Do incandescent bulbs dim with age?
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MolaKule
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Is there a plastic bezel or covering or shield around or in front of the light?
If not, check the voltage first and then replace bulbs if voltage is not over 14.0 Volts.
If not, check the voltage first and then replace bulbs if voltage is not over 14.0 Volts.
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JHZR2
Staff member
are the lenses glass or plastic?
I think the filament redistributes with age, I suppose if it is smaller (metal vapors recondense on the glass and not on the filament), then it cannot handle as much wattage, and thus burns less bright.
Just a speculation.
Im sure your wiring harnesses might get old and have higher contact resistance with age and corrosion - might want to clean them up and then put a bit of dielectric on them... Its also not uncommon to see a bit of rust on the spades of the lightbulb itself...
JMH
I think the filament redistributes with age, I suppose if it is smaller (metal vapors recondense on the glass and not on the filament), then it cannot handle as much wattage, and thus burns less bright.
Just a speculation.
Im sure your wiring harnesses might get old and have higher contact resistance with age and corrosion - might want to clean them up and then put a bit of dielectric on them... Its also not uncommon to see a bit of rust on the spades of the lightbulb itself...
JMH
Originally Posted By: MolaKule
Is there a plastic bezel or covering or shield around or in front of the light?
If not, check the voltage first and then replace bulbs if voltage is not over 14.0 Volts.
Why would you replace the light bulbs if the voltage is not over 14 volts? If your voltage is low, check the battery, wiring, or alternator.
Is there a plastic bezel or covering or shield around or in front of the light?
If not, check the voltage first and then replace bulbs if voltage is not over 14.0 Volts.
Why would you replace the light bulbs if the voltage is not over 14 volts? If your voltage is low, check the battery, wiring, or alternator.
Supposedly halogen bulbs don't dim as badly b/c every time they're brought up to temp, whatever fuzz is on the glass revaporizes, perchance to land on the filament again.
Though this thing probably came with halogen bulbs, a cheapo service replacement could have been stuck in at some point.
If you look through the lens and see a smaller bulb inside, it's halogen.
Though this thing probably came with halogen bulbs, a cheapo service replacement could have been stuck in at some point.
If you look through the lens and see a smaller bulb inside, it's halogen.
Thanks all, I'm pretty sure the Wag has halogen seal beams. The wiring is generally in poor shape. 20 yrs old and none too good to begin with. I thought I had read somewhere that bulbs fade in time. Another thing to add to the to do list. "Repair / Rewire Jeep headlights"
For what it's worth, I found this on the web. If it's true, it explains a few things, including why you should use gloves when handling quartz/halogen bulbs.
Quote:
"Over time the lamp filament evaporates and coats the inside of the bulb. This is the origin of the black shadows you see in old lightbulbs. The brighter the light(hotter the filament) the quicker this happens. To lessen this blackening, a halogen such as iodine is introduced into the bulb. The halogen induces the evaporated filament to return the the filament rather than travel to the bulb but doesn't stop it completely. The process is slowed enough that it is possible to greatly increase the current and heat in the filament until glass will no longer work and quartz instead is used for the bulb material, hence quartz-iodine lamps. The downside is that quartz is eroded by the salts and oils on your fingers so the bulb must be cleaned with alcohol and handled with gloves when installing or it can explode."
In my experience, in replacing an old bulb, I tend to do it in pairs, even when using the same exact bulb. If you don't, the old one you didn't replace seems dimmer and more "orange" than the new one. Could be those dark spots/ reduced filament size described above.
Quote:
"Over time the lamp filament evaporates and coats the inside of the bulb. This is the origin of the black shadows you see in old lightbulbs. The brighter the light(hotter the filament) the quicker this happens. To lessen this blackening, a halogen such as iodine is introduced into the bulb. The halogen induces the evaporated filament to return the the filament rather than travel to the bulb but doesn't stop it completely. The process is slowed enough that it is possible to greatly increase the current and heat in the filament until glass will no longer work and quartz instead is used for the bulb material, hence quartz-iodine lamps. The downside is that quartz is eroded by the salts and oils on your fingers so the bulb must be cleaned with alcohol and handled with gloves when installing or it can explode."
In my experience, in replacing an old bulb, I tend to do it in pairs, even when using the same exact bulb. If you don't, the old one you didn't replace seems dimmer and more "orange" than the new one. Could be those dark spots/ reduced filament size described above.
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Originally Posted By: andyd
The headlights on my 88 Jeep are dim, they look amber. is this due to their age or low voltage?
Halogen bulbs' color temperature remains pretty consistent until they burn out. You are looking at low voltage if the the lights put out much warmer light than they used to.
The headlights on my 88 Jeep are dim, they look amber. is this due to their age or low voltage?
Halogen bulbs' color temperature remains pretty consistent until they burn out. You are looking at low voltage if the the lights put out much warmer light than they used to.
Kestas
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I once had an odd situation where the original lamps in my 91 Marquis were dim because after twelve years the reflective coating wore off. The original lamps were plastic, the replacements were glass.
Originally Posted By: Kestas
I once had an odd situation where the original lamps in my 91 Marquis were dim because after twelve years the reflective coating wore off. The original lamps were plastic, the replacements were glass.
I see a lot of this on taillights of old cars that aren't as bright as they once were. One really notices on a concours-level restoration of a 70's muscle car that the tails are as bright as one would expect from modern vehicles.
Ford and plastic headlights should be forcefully seperated:
I once had an odd situation where the original lamps in my 91 Marquis were dim because after twelve years the reflective coating wore off. The original lamps were plastic, the replacements were glass.
I see a lot of this on taillights of old cars that aren't as bright as they once were. One really notices on a concours-level restoration of a 70's muscle car that the tails are as bright as one would expect from modern vehicles.
Ford and plastic headlights should be forcefully seperated:
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Jefe, someone or something has been gnawing on the edge of your car's hood.
Originally Posted By: moribundman
Halogen bulbs' color temperature remains pretty consistent until they burn out. You are looking at low voltage if the the lights put out much warmer light than they used to.
This is correct about the halogens. Though the old incandescent sealed beams would dim/yellow with age until they finally burned out. I remember when I replaced the incandescent sealed beams with halogen sealed beams on the aircooled beetle in the early 80s. Made a big difference. Euro H-4s would have been even better had I known about them.
Halogen bulbs' color temperature remains pretty consistent until they burn out. You are looking at low voltage if the the lights put out much warmer light than they used to.
This is correct about the halogens. Though the old incandescent sealed beams would dim/yellow with age until they finally burned out. I remember when I replaced the incandescent sealed beams with halogen sealed beams on the aircooled beetle in the early 80s. Made a big difference. Euro H-4s would have been even better had I known about them.
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Originally Posted By: John R
This is correct about the halogens. Though the old incandescent sealed beams
Tungsten bulbs, to which you are referring, are also "incandescent" bulbs. Yes, tungsten lights dim and their color temperature output drops with age very noticeably. I have not seen tungsten bulbs used in cars during my lifetime.
This is correct about the halogens. Though the old incandescent sealed beams
Tungsten bulbs, to which you are referring, are also "incandescent" bulbs. Yes, tungsten lights dim and their color temperature output drops with age very noticeably. I have not seen tungsten bulbs used in cars during my lifetime.
The bulbs in question were halogen seal beams. I replaced them yesterday with the halogen seal beams from my parts Jeep. The original bulbs had lost their air tight seal and moisture had flaked off the reflective coating. The left bulb had collected a 1/2" water inside it.
I also pushed the connectors out of the harness plugs and wire brushed the corrosion off. Then, I added a piece of 10 gauge cable to bond the lights' ground to the - battery terminal. This gained me a volt when measured across the plugs. This is the 3rd extra ground I've added to the Grand Wagoneer. Every one has improved the system somewhat. The wiring was none too good to start with and age hasn't improved it.
I also pushed the connectors out of the harness plugs and wire brushed the corrosion off. Then, I added a piece of 10 gauge cable to bond the lights' ground to the - battery terminal. This gained me a volt when measured across the plugs. This is the 3rd extra ground I've added to the Grand Wagoneer. Every one has improved the system somewhat. The wiring was none too good to start with and age hasn't improved it.
Andyd,
Yes Halogen bulbs do dim with age due their design. When lit tiny pieces of the tungsten filament evaporate off, the halogen gas, and in some cases tiny amounts of Bromine, or Xenon act as a barrier to keep the filament molecules from depositing on the glass, which happens eventually. From what I've read and experienced It's best to replace halogen bulbs every three years. Your problem could be either or, or both. Low voltage will dim the light output and make it look "Amber" it also shortens life expectancy very quickly.
Yes Halogen bulbs do dim with age due their design. When lit tiny pieces of the tungsten filament evaporate off, the halogen gas, and in some cases tiny amounts of Bromine, or Xenon act as a barrier to keep the filament molecules from depositing on the glass, which happens eventually. From what I've read and experienced It's best to replace halogen bulbs every three years. Your problem could be either or, or both. Low voltage will dim the light output and make it look "Amber" it also shortens life expectancy very quickly.
Wouldn't low voltage make the bulb last longer, but put out less light?
Kestas
Staff member
To a point. We've worked on problems with bulbs working at lower voltages where the filaments were having whisker growth problems, resulting in shortened life.
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