921 / CHMSL recommendations?

Buck91

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Question for everybody here, though its kind of two part. I am looking to reseal and/or replace my F150's CHMSL due to known leakage issues in this application. I'd like to just RTV it in place and not have to worry about it again, but I don't want to deal with trying to remove RTV from a painted body surface to replace bulbs. Are there any good quality LED CHMSL assemblies available? If not, what is my best bet for a rock solid reliable LED replacement for the 3x 921 bulbs in there?
 

-Virgil-

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There is no LED bulb that will effectively and safely replace 921 bulbs in a red-lens application.

You don't mention what year your F150 is; that information would make it easier to answer your question helpfully.
 

Buck91

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There is no LED bulb that will effectively and safely replace 921 bulbs in a red-lens application.

You don't mention what year your F150 is; that information would make it easier to answer your question helpfully.

Sorry, its a 2011. They are known for leaking CHMSL due to a rather crappy foam gasket.
 

Alaric Darconville

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I'mma say "No" on that thing. I mean, look at the picture they provide of the wiring. That's the attention to detail they give to making the wiring? Photometry has got to be a similar joke.
 

Buck91

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I'mma say "No" on that thing. I mean, look at the picture they provide of the wiring. That's the attention to detail they give to making the wiring? Photometry has got to be a similar joke.

Are you talking about the bent out of shape "pin" on the connector? Totally missed that until you make me re-examine the pics...
 

Alaric Darconville

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Illegitimate product recommendation deleted by moderator as per rule 11
From the light center length mismatch to the incredibly large heatsink, this will result in so much optical noise and output shadowing that the lamp may visibly light but not fulfill the required CHMSL function.
 
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Alaric Darconville

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Illegitimate product recommendation deleted by moderator as per rule 11
It doesn't take a huge understanding of optics to see how it is more likely to NOT work correctly than for it to work correctly.
A real 921 is mostly clear, it has a 37.8mm maximum overall length, a 20.6mm light center length, and a 16mm outside diameter. The area all around the LEDs is not free of obstruction, causing shadowing and optical noise just like the heatsinking at the extreme end of this thing. The 3 LEDs attempt to duplicate the arched filament but they're not an arched filament. They're also not perfectly axially centered; moving the light sources away from the focal point of the reflector.

This is not going to work.
 
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-Virgil-

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czechopino, the lighting modifications/products you're recommending are illegal and unsafe. Rule 11 of this board prohibits advocating illegal or dangerous activity, so your recommendations have been deleted.
 

-Virgil-

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-Virgil-

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That's interesting, the packaging says 0.9w. It looks like a similar bulb is available in the Osram LEDriving line, but it has a white backboard instead of black and is rated 1.4w.

The design looks promising, it reminds me of the very good Philips gen1 back-to-back design, though the Philips bulb had its emitters angled slightly forward, and this Osram/Sylvania bulb does not -- which probably means a no-go for the Osram/Sylvania design in Fresnel optic lamps that require light emitted straight out in line with the bulb's axis. But it doesn't look like a very expensive pair of bulbs, so pick up a set (I would go for the 1.4w items, myself), refer to the performance test method -- you will have to lean heavier on the meter readings with the LED versus the standard bulb, because there is no left + right CHMSL to compare -- and let us know what you find out.
 

jzchen

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Thank you again Virgil. I'm afraid I lost my smart a while back. I checked the other cars in the household and none have a CHMSL requiring a 921 bulb. (I'm not going to be able to test this one. Since I stumbled across it I thought I'd bring it up)…
 
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