Sealed beam for 1970

[Charles W.]

My 1970 still has all 4 original sealed beams and 3 of the 4 still work. One high beams doesn't work. Where would one find an original style sealed beam compatible with the fiber optics? I presume there is no work around to get the fiber optics to work with a replacement bulb?

[Terry M.]

Re: Sealed beam for 1970

My 1970 still has all 4 original sealed beams and 3 of the 4 still work. One high beams doesn't work. Where would one find an original style sealed beam compatible with the fiber optics? I presume there is no work around to get the fiber optics to work with a replacement bulb?

Any old sealed beam lamp will work with the fiber optic system. All of the components that are unique to that system are part of the wiring harness, and not the lamp. A look at the appropriate page in the 1970 AIM will confirm this. Try not to lose the foam collar that channels the light from the back of the lamp; where the vacuum is extracted during manufacture, to the end of the fiber.

If your concern is judging the TIM&JG has pictures of the appropriate face of the lamp as well as configuration of the internal components. Of course you have examples of these details on your existing, non-functional, lamp. Duplicating those will be a challenge limited only by the size of your wallet.

There is an orange stamp on the back of the lamp that has the manufacturer's logo and a date code. For obvious reasons this is not judged, and the chances of duplicating this feature are beyond calculation.

Enjoy your 1970.

[Joe L.]

Re: Sealed beam for 1970

My 1970 still has all 4 original sealed beams and 3 of the 4 still work. One high beams doesn't work. Where would one find an original style sealed beam compatible with the fiber optics? I presume there is no work around to get the fiber optics to work with a replacement bulb?

Charles-------


As Terry mentions, as far as functionality of the fiber optic system is concerned, just about any sealed beam will do. The important feature is the small extension in the center of the rear of the bulb, between the electrical contacts. Light has to be transmitted through this extension for the fiber optic transmission to be functional. Most, if not all, replacement sealed beams should have this extension as it is necessary for the manufacturing process. However, I suppose it is possible that very recent manufacturing process changes might obviate the need for it. So, check the sealed beam before you buy it. Original sealed beam extensions were dyed blue. Others might be a different color. As long as the extension is present and is not opaque, the sealed beam should work fine with fiber optics.

As Terry also mentioned, the seals should be preserved. They are necessary if the fiber optics are to work at full intensity. These seals are a type of foam rubber and may be deteriorated after 50 years. If so, reproductions are available.

Attached are photos of the rear of an original Guide sealed beam showing the center extension.

DSCN3930.jpg

[Jeffrey S.]

Re: Sealed beam for 1970

Just one slight comment- from my experience in replacing the bulbs in my 69 over the past 50 years, i have found that most of the aftermarket/parts store bulbs have the nipple painted black which won't work with fiber optics. Be sure to check that if you go the aftermarket route.
Jeff

[Terry M.]

Re: Sealed beam for 1970

Just one slight comment- from my experience in replacing the bulbs in my 69 over the past 50 years, i have found that most of the aftermarket/parts store bulbs have the nipple painted black which won't work with fiber optics. Be sure to check that if you go the aftermarket route.
Jeff

Thanks for the info Jeff. I didn't know that. It has been quite a few years since I replaced a sealed beam lamp, and even at that I used NOS lamps.

[Charles W.]

Re: Sealed beam for 1970

Guys, thanks for the replies. A lot of good information. The seals are long gone. That's probably why the FO display was weak. I have ordered the FO seals. I have learned that ZIP sells reproduction bulbs advertised as compatible with the FO and 25% brighter than originals.

[Mike E.]

[Terry M.]

Re: Sealed beam for 1970

Terry: This thread piqued my interest as I [still] have three T3 lamps (one outer, two inner) that I harvested from a 1970 Chevelle wagon I parted out in the late 70s. One of the inner has the orange stamp and a 3-charachter code, but I can't make it out well enough to "make it work" and figure out the date. Can you provide any hints as to the format of the date code? I know the wagon was a 70, and that these lamps came out of it; another means of confirmation would be cool. Thanks.

Someplace I have seen a print detailing the logo. I'll look to see what I can find, but Cedar Rapids Regional and then Bloomington Gold will interfere. I'll try though.