Replace Backup Bulb with led
Junior Member
Joined: Oct 2020
Posts: 8
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From: Ohio
I have come to find out 7440 bulbs are what I need for back-up lights. Going to pick up some Sylvania Zevo LED replacements for my W21W bulbs. The 194 bulbs are for license plate illumination.
Last edited by BobBuckeye; Oct 30, 2020 at 01:34 PM.
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From: So Cal
Community Team
Joined: Jun 2016
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From: Vermont
Ask any of the companies that make them or do a bit of research. They make white, red and amber for a reason. You’ll get much better results with leds that are the same color as the lense they’re behind.
the bulbs that were in there before were 2700k incandescent. 5000-6500k leds turn the taillights pale red/ pink.
the bulbs that were in there before were 2700k incandescent. 5000-6500k leds turn the taillights pale red/ pink.
Senior Member
Joined: Apr 2011
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Ask any of the companies that make them or do a bit of research. They make white, red and amber for a reason. You’ll get much better results with leds that are the same color as the lense they’re behind.
the bulbs that were in there before were 2700k incandescent. 5000-6500k leds turn the taillights pale red/ pink.
the bulbs that were in there before were 2700k incandescent. 5000-6500k leds turn the taillights pale red/ pink.
Community Team
Joined: Jun 2016
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From: Vermont
(Another teachable moment for this ole dawg)
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Actually, he's entirely correct. Unlike an incandescent bulb which is polychromatic and produces roughly the same amount of light across the entire visible spectrum, and LED is monochromatic (or, more accurately, it's typically produces a few different wavelengths across the spectrum, but not a complete spectrum). White LEDs are actually (in most cases) a blue/violet LED with a coating of a YaG phosphor... producing a spectrum somewhat like this (and compared with daylight):
Filters work by only allowing a specific wavelength (or, more precisely, a narrow band of wavelengths) through. If you use a filter that only allows a spectrum which isn't produced in great quantity by the white LED, the output will be crap.
Thus, your best bet is a filter matched to the output wavelength of the LED. Thus, a red filter in front of a red LED, etc. Or, go to a clear filter, like most emergency vehicle lights have gone to.
Filters work by only allowing a specific wavelength (or, more precisely, a narrow band of wavelengths) through. If you use a filter that only allows a spectrum which isn't produced in great quantity by the white LED, the output will be crap.
Thus, your best bet is a filter matched to the output wavelength of the LED. Thus, a red filter in front of a red LED, etc. Or, go to a clear filter, like most emergency vehicle lights have gone to.
