Fiber optic replacement
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
Fiber optic replacement
Has anyone installed complete new fiber optic harnesses?
Im battling troubleshooting them in my 68. Some work but are dim, some don’t work at all. Debating biting the bullet and replacing the entire setup but it looks pretty difficult. Curious if anyone has done it
Im battling troubleshooting them in my 68. Some work but are dim, some don’t work at all. Debating biting the bullet and replacing the entire setup but it looks pretty difficult. Curious if anyone has done it
Team Owner
Joined: Jan 2006
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From: Crossville TN
Unless the F/O cables are pinched (significantly) or cut, there is absolutely NO reason to replace them. The problem with "dim" output on the interior panel is that little of that particular bulb's light is getting into the F/O cable at the lamp. This is usually due to having the F/O cable lenses (inside the lamp housing) being dull, dirty or spray painted so that any light from that bulb is reduced or even blocked.
Is my vette stock?? HAHA
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I bought a new front harness with the fiber optics wrapped in it and a separate rear. Its easy to run but you need to pull the rear carpet to the side and pull the seats to get under the front carpet. To get through the rear grommet I split it, then slid the new harness iin once i had it placed.
As 7T1 said dull ones need the tips and lenses to be cleaned and non working ones investigated. To trouble shoot i take working ones and get a bright flashlight and tape the end to the glass without the colored bulb end and manipulate it until i figure out a way to get a good light inside. Then i replicate that with the others. They are just glass wires so they only transmit light, no electricity as my PO found out when he cut mine and spliced them together with those blue clamp style connectors. So they need to be pointed directly at the light source
Clean the tips and test your lines and you can figure out if they need replacing before you get into that. For my rear lines, they were original and my wiring was still good so instead of unwrapping the whole harness I ust ran the new FO harnes next to the old one. If my rear wiring gets brittle and fails I'll replace everything then.
As 7T1 said dull ones need the tips and lenses to be cleaned and non working ones investigated. To trouble shoot i take working ones and get a bright flashlight and tape the end to the glass without the colored bulb end and manipulate it until i figure out a way to get a good light inside. Then i replicate that with the others. They are just glass wires so they only transmit light, no electricity as my PO found out when he cut mine and spliced them together with those blue clamp style connectors. So they need to be pointed directly at the light source
Clean the tips and test your lines and you can figure out if they need replacing before you get into that. For my rear lines, they were original and my wiring was still good so instead of unwrapping the whole harness I ust ran the new FO harnes next to the old one. If my rear wiring gets brittle and fails I'll replace everything then.
Last edited by Rescue Rogers; Jan 30, 2020 at 06:32 AM.
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
I know at least half of my fronts are broken.
messed with the headlights a bit last night, ran out of time. PO must have broken then and tried a splice, didnt work. trying to splice it but doesnt seem like it wants to cut nice and clean- yes I'm using a new razor blade. fiber cables seem very brittle and want to crack when i try to cut.
messed with the headlights a bit last night, ran out of time. PO must have broken then and tried a splice, didnt work. trying to splice it but doesnt seem like it wants to cut nice and clean- yes I'm using a new razor blade. fiber cables seem very brittle and want to crack when i try to cut.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
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It sounds like replacement is warranted. If you replace just the FO harness you'll need to unwrap the entire harness and rewrap it..or install a new one as a stand alone
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
how is the fiber optic held into the headlight socket?
on both my drivers side headlight bulbs, the fiber optics are cracked at the bend where the wiring harness comes from the bulbs and joins the main harness. If I put my flashlight to the cable there- i get the lights to light up in the console. I was thinking of just replacing the last couple ft of fiber but dont know how to get them out of the headlight socket
on both my drivers side headlight bulbs, the fiber optics are cracked at the bend where the wiring harness comes from the bulbs and joins the main harness. If I put my flashlight to the cable there- i get the lights to light up in the console. I was thinking of just replacing the last couple ft of fiber but dont know how to get them out of the headlight socket
Team Owner
Joined: Jan 2006
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From: Crossville TN
The headlamp F/O is fitted into the headlamp electrical socket. When the socket is placed on the lamp pins, the end of the F/O cable is aimed at the 'nipple' at the rear of the lamp which has no coating on it. As originally built at the factory, there are some 3/8" diameter black plastic tubes inserted over the lamp nipple and between the lamp and socket. This was to keep ambient light from entering the F/O cable. Those little tubes are very well replicated by using 3/8" black shrink tubing cut to about 1/2" - 5/8" length.
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
The headlamp F/O is fitted into the headlamp electrical socket. When the socket is placed on the lamp pins, the end of the F/O cable is aimed at the 'nipple' at the rear of the lamp which has no coating on it. As originally built at the factory, there are some 3/8" diameter black plastic tubes inserted over the lamp nipple and between the lamp and socket. This was to keep ambient light from entering the F/O cable. Those little tubes are very well replicated by using 3/8" black shrink tubing cut to about 1/2" - 5/8" length.
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Is my vette stock?? HAHA
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From: Im not allowed to tell you
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its held into the plug with a brass ferrule that is crimped onto the FO line and is pressed into the plug. The foam rubber piece was help in by the weird glass nipple.
http://repairs.willcoxcorvette.com/1...adlamp-collar/
http://repairs.willcoxcorvette.com/1...adlamp-collar/
Last edited by Rescue Rogers; Jan 30, 2020 at 06:55 PM.
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,145
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
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2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
the hole is where the end sees the light from the nipple
the hole in the center is where the brass is pressed into
thats it hanging next to the plug. ITs called a ferrule. I thought it had barbs until I went out and took a pic
Last edited by Rescue Rogers; Jan 30, 2020 at 06:56 PM.
Melting Slicks
Joined: Feb 2017
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From: New York
2017 C3 of the Year Finalist
St. Jude Donor '20- '21
Great info on a project on my to do list!!!! So the fiber optic harness is wrapped up with the wiring harness? So to install a new fiberoptic harness you would need to unwrap install and re wrap the wiring harness? Thanks Ike
Is my vette stock?? HAHA
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Or, if you wanted to keep it looking original, unwrap and rewrap. It just depends on the amount of effort an your end goal you want
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
How hard was it to replace just the rear fiber optic harness?
I messed with my car for about 2 hours today. I might be able to salvage the front. I can get most of them to illuminate with an led flashlight. Only problem is they are pretty dim with the bulbs
but the rear may be a lost cause. All 3 are now “working” but incredibly dim. Can’t actually tell they are even on once the F/O cables are installed. I have a feeling they may have gotten sliced somewhere along the route, and if I’m going to be tracing the route I’m just putting a new harness in
I messed with my car for about 2 hours today. I might be able to salvage the front. I can get most of them to illuminate with an led flashlight. Only problem is they are pretty dim with the bulbs
but the rear may be a lost cause. All 3 are now “working” but incredibly dim. Can’t actually tell they are even on once the F/O cables are installed. I have a feeling they may have gotten sliced somewhere along the route, and if I’m going to be tracing the route I’m just putting a new harness in
Melting Slicks
Joined: Feb 2017
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From: New York
2017 C3 of the Year Finalist
St. Jude Donor '20- '21
Thanks I don't want to hijack Tiger Joe's thread. I will post a new one at some point. Mine has a break somewhere but I have yet to figure out were. Ike
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,145
Likes: 9,278
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
How hard was it to replace just the rear fiber optic harness?
I messed with my car for about 2 hours today. I might be able to salvage the front. I can get most of them to illuminate with an led flashlight. Only problem is they are pretty dim with the bulbs
but the rear may be a lost cause. All 3 are now “working” but incredibly dim. Can’t actually tell they are even on once the F/O cables are installed. I have a feeling they may have gotten sliced somewhere along the route, and if I’m going to be tracing the route I’m just putting a new harness in
I messed with my car for about 2 hours today. I might be able to salvage the front. I can get most of them to illuminate with an led flashlight. Only problem is they are pretty dim with the bulbs
but the rear may be a lost cause. All 3 are now “working” but incredibly dim. Can’t actually tell they are even on once the F/O cables are installed. I have a feeling they may have gotten sliced somewhere along the route, and if I’m going to be tracing the route I’m just putting a new harness in
I just ran it next to the original harnes and zipped them together. The hardest part was getting it through the rear firewall grommet. I split that from the center out and laid it in next to the original. You have to peel back the rear carpet and remove the front seats. It runs down behind the rear quarter trim and under the carpet behind the seat, under the side of the center console.
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
Well ordered a new rear harness last night. So while I wait for that to arrive I messed with the front.
Right now now I managed to get 4 of the 6 working, albeit a lil dim. I’m struggling to get a good splice and I think that’s my issue, losing a lot of light in the connection.
Might order a piece of bulk FO cable so I can practice splicing.
Right now now I managed to get 4 of the 6 working, albeit a lil dim. I’m struggling to get a good splice and I think that’s my issue, losing a lot of light in the connection.
Might order a piece of bulk FO cable so I can practice splicing.
Melting Slicks
Joined: Feb 2017
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From: New York
2017 C3 of the Year Finalist
St. Jude Donor '20- '21
Tiger Joe. I am sure how you are splicing these F-O but if I am not mistaken some of the vendors sell repair kits. I am not sure how good they are and if they will make your splices any better but it may be worth taking a look.
I am following along your adventure. My front harness is cut somewhere but still working on the front grill area for now. Ike
I am following along your adventure. My front harness is cut somewhere but still working on the front grill area for now. Ike
Thread Starter
Drifting
Joined: Nov 2016
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From: Pittsburgh PA
so just an update here for anyone else searching.
I replaced my rear fiber optic harness- wasnt terrible difficult. hardest part was getting in thru the grommet at the rear of the body. i got sidetracked and havent got back to the fronts, but i have all of them working except for the 2 passenger headlights.
on a side note- I did order the fiber optic splice kit from corvette america, just because I wanted to see if it had anything "special" in it, or had any directions in it maybe i wasnt doing. what a joke. it was literally like 2 ft of fiber cable and a piece if shrink tube.
I replaced my rear fiber optic harness- wasnt terrible difficult. hardest part was getting in thru the grommet at the rear of the body. i got sidetracked and havent got back to the fronts, but i have all of them working except for the 2 passenger headlights.
on a side note- I did order the fiber optic splice kit from corvette america, just because I wanted to see if it had anything "special" in it, or had any directions in it maybe i wasnt doing. what a joke. it was literally like 2 ft of fiber cable and a piece if shrink tube.
Team Owner
Joined: Jan 2006
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From: Crossville TN
The important issues with achieving a good splice on a F/O cable are:
Clean, straight butt-joint cuts to the two pieces to be "mated". The smoother the cuts (very sharp instrument) and the better the face-to-face fit, the higher the light transmission rate. I have heard that some folks have used Super Glue (cyanoacrylate) to 'marry' that butt joint; and that it has positive result if done well. I've not tried it, but might be useful research. Trapping the fiber bundle to keep it as a compressed cable is important, as well. Might want to use some shrink wrap on the spot needing to be cut, so the end stays intact.
Clean, straight butt-joint cuts to the two pieces to be "mated". The smoother the cuts (very sharp instrument) and the better the face-to-face fit, the higher the light transmission rate. I have heard that some folks have used Super Glue (cyanoacrylate) to 'marry' that butt joint; and that it has positive result if done well. I've not tried it, but might be useful research. Trapping the fiber bundle to keep it as a compressed cable is important, as well. Might want to use some shrink wrap on the spot needing to be cut, so the end stays intact.