68-69 Fiberoptic Question.

[Chuck G.]

I've been going through the 69, getting thing ready for Founders ops check in Long Island. The front parking light fiberoptic display inside the car has always been less bright than the others. Looked at it today...got me thinking. I have clear lenses with amber bulbs in the front parking lights. On the back of the parking light housing is the "hole" for the fiberoptic, a gray rubber bezel with an amber plastic insert. The cable goes into the amber plastic insert and the entire assembly is then covered with a boot. If I have amber bulbs, do I also need to have amber plastic inserts? Could this be why the display is dull inside the car? If amber colored light is being generated, shouldn't it have a clear plastic insert? I realize that on the taillights you need red plastic, since the bulbs are clear. BTW, the rear backup lights have clear plastic inserts, but they're much smaller than the fronts. Any thoughts on this? Chuck

[Jerry Clark]

Re: 68-69 Fiberoptic Question.

Hi Chuck:

I believe the answer is yes, you need the amber insert or you could possibly transmit sunlight to the interior. The fiberoptics read whatever light is present , if I understand the system correctly. I was replacing the loom that contained the fiberopticss on my 69, with the optics dangling under the forward surround I noticed the interior indicating it was lit although only partially installed, it was the optics transmitting sunlight from the open, southern facing garage door. I know this doesn't answer the brilliance part of your inquiry but I think you may need the colored insert.

jer

[Tony H.]

Re: 68-69 Fiberoptic Question.

Hello Chuck,

A while back, I had a similar situation with my 70 fiber optics. One day when I was doing some detailed cleaning in the front lights and tinkering with the wiring behind the lights, I removed the bulb from behind and found that the light bulb had some paint overspray. I cleaned off the overspray with my thumbnail and voila. What a difference in brightness at the console that made! Hope this does the trick. I also cleaned up the contacts in the bulb socket so this may also have had an effect on the brightness of the bulb.

Tony

[Jerry Clark]

But Wait...

I hate adding after the original post but, If I remember correctly aren't the lenses in the console tinted the appropriate color also or is my recollection incorrect, (AGAIN), how much amber is necessary ? I'd try removing the amber lens and see how the console light is effected.

jer

[Jim R.]

Re: 68-69 Fiberoptic Question.

While ya'll are on this subject, I'm having a problem with my right rear fiber optic. It does not light up at all.

I had the connection to the console plate checked by the mechanic that pulled my transmission and he said everything looked O.K. He and I both took the lens off the rear light, independently, and nothing looks amiss there either.

Any ideas on how to further troubleshoot this problem?

Thanks.......Jim

[Jack H.]

Re: 68-69 Fiberoptic Question.

On my '71, one side was bright the other dim. Pulled 'em and found random paint overspray from last re-shoot (painter left 'em dangling without mask). Cleaned up the 'look' end of the offending side and it brightened up, but still not as same as the other side....

A year or two back there was an article in Restorer about the absolute length of the fiber pickup coming out of the ferrule and its fit inside the side marker housing. Bottom line was: (1) too short and pickup falls away from bulb causing low intensity, or (2) too long and pickup strands 'bottom' and look away from the bulb also causing intensity loss.

Played with my car (take a lot of patience to remove the ferrule without breaking, trim as required, and re-attach the ferrule) and did see a big improvement. Also, you might what to check that candlepower of bulbs agrees with factory specs....

If you're using Guide halogens instead of tungsten incandescents up front the marker lamps can 'appear' dim because adjacent cockpit fiber monitors are being 'over illuminated' at their source. Ditto for backside -- have bulbs been changed over time and you've got 'apples/oranges' in various sockets....

[Tony H.]

Re: But Wait...

Jerry,

If my recollection is correct, I believe that the front lenses at the console are clear plastic with a dab of green pigment on the center lenses where the low beam fiber optics lead to and a dab of red pigment on the inner lenses where the high beams lead to. The outer lenses are clear and get their color from the bulb or fiber optic lens at the other end of the fiber optic (not the parking lens).

[Juliet P.]

Re: 68-69 Fiberoptic Question.

Chuck, On my '70 the fiber optic panel for the front lights appears to have a different colors at the console (red, amber, green) whereas the panel for the rear lights appear uniform white. This observation was made in the dark garage by shining a flashlight at an angle onto the console fiber optic lights. I think my center console is original, but not having purchased the car new (I was only 5 at the time!) I can't swear to it. (grin)

Anyways, I can certainly see your logic being correct. It works for my 1970! And factoring in the GM production low-cost factor, I can see them skipping the dye in certain parts to save a nickle. It might be interesting to see the history of these fiberoptic parts.

What are the fiberoptic console like on the '69? Are front & rear both colored or clear? If the console panel is colored for the front lights, additional coloration at the light source is redundant, and might actually cause a reduction in the candlepower traveling through the fiberoptic cables. This I would think applies to the cover thing and the bulb both. However, if the rear console panel appears to be uncolored I would expect there to be color at the light source instead.

Very interesting thread. I thought I had a brake problem a while back, but it was the sun shining on the lens. The ideas for overspray are great. My green front fiber optics are very dim. I'm sure that's overspray in my case. I've got it everywhere else, why not the lights too! Heck the last Bubba the painter removed the lenses on the rear and painted the shiney parts blue! EEK!

Good Luck at the L.I. meet! ~Juliet

[Robert C.]

Re: 68-69 Fiberoptic Question.

Chuck, Don't for get , there are little rubber hose pieces that slide on the rear of the headlamps. It's the glass nipple that protrudes at the middle rear of each lamp. The small rubber tube slides over the nipple which focas the light onto the fiber optic end. The other thing is to carefully clean the end of the optic bundle with a Q-tip and contact cleaner. The big problem in brillance is the years of dirt. While you are doing the cleaning make sure all reflector are clean. You may want to paint the inside reflecting areas in the rear lights white as I believe they came that way from the manufacturer for fiber optics reflectivity. Terry McManmon wrote a great article on fiber optic cleaning/troubleshooting in the Restorer 6 or 7 years ago.


Texas Chapter NCRS

[Klaus Friedrich, #33362]

Re: 68-69 Fiberoptic Question.

Hello Chuck, your problem is quiet normal. Take a look to the capacity of the bulbs. The parking light got only 5W, while the other have much more capacity - in this way they are much brighter. If you run the flash signals you should see that it is brighter than. The high beam is even brighter than the low beam. Take a good look to the lenses, you should recognize it.

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