Good Morning CF,

I am continuing to work on replacement of my LH and RH Tail Light fiber optic cables. Have tried everything I can think of to get the rear tail light fiber optics to display and have concluded replacement is my final best option. They were cut years ago when my son had flow master mufflers installed in 2010 and the muffler shop just re-taped the LH tail light wires, LH marker wires, and FO cables they damaged with electrical tape. Thank you for that.

Q1:
I need help sourcing the black rubber plug or grommet (AIM page 431) showing the body wiring & relay mounting. This is the lager grommet that secures the fiber optic cables and the tail light and license plate wires in the rear main wire harness. I've searched Corvette Central and Willcox but I am obviously not calling the part by the correct description. Grommet, wire harness grommet, plug, wire harness plug, etc.

Q2:
Once I find the replacement grommet part, what is the easiest way to remove the old rubber wire harness grommet. I was hoping the grommet was a 2-piece rubber plug that would be easy to split and then just run the replacement fiber optic cables through the rear compartment opening and put the 2-piece rubber plug (grommet) back in place. Then, re-wrap the rear wire harness and use a seam cement about 2" on either side of the grommet to water-proof the hole and wires and fiber optic cables. Does not look like that is gonna happen. Do I have to cut the old grommet off? And what is the easiest way to reinstall the new grommet if these are not 2-piece rubber grommets?

Suggestions and recommendations appreciated.





fiber optic cables separated from rear wire harness

 

What are the dimensions of the grommet? It has been several years since I worked in this area. That Grommet most likely came as an assembly with the harness so there would be no part number to work from.

https://www.steelerubber.com/marine-...-plugs-bumpers

 

Hey PJO,

Excuse the hand sketch and rough dimensions for the grommet.

 

Hello PJO,

I put a call into Steele Rubber (thank you for the link) got an email address, and sent the drawing / dimensions / and photos of the grommet to them to see if they might be able to help. Guess I am at a point where I am thinking that the only way I am going to get my old fiber optic cables out and thread the new donor '69 fiber optics cables into this car is to borrow one of my wife's nice serrated steak knives and carefully cut from the outside edge of the grommet to the center of the grommet where the wires and fiber optic cable bundle is located. Then, try to slide the fiber optic cables out through the slit in the grommet (without cutting any of the tail light or license plate power wires of course). Ruled out, but did consider, just cutting the tail light, license plate, sending unit wires and splicing then all back into the original grommet.

Looks like even if I can find a replacement grommet that it will be a fully intact molded rubber piece which I will have to cut too, in order to just thread the new fiber optic cables.

Now I know why I exhausted all of the other possible options and solutions for repairing the old fiber optic cables. What a pain!

 

The biggest issue in splicing a fiber optic cable is they most be cut perfectly square to each other. Then sealed keeping everything in line.
You other alternative is to purchase a rear harness as everything will be ready for install or just the fiber optic harness.

https://www.lectriclimited.com/wire-...harness-111404

https://www.lectriclimited.com/repai...ly-rear-lights

https://www.corvettecentral.com/68-7...-kit-nd-663137

 

Yep, I have attempted the 90 degree splice a dozen times - no luck. Wire cutter, X-acto knife, razor blade, etc. Filed the ends with emery paper, finger nail file, wet sand with 800 grit sand paper, just bare cut end.

I sourced a complete rear wire assembly from a 1969 coupe out of California with the intention of replacing my damaged fiber optic cables with '69 fiber optic cables out of a donor car. I've already used the donor harness to fix my LH marker wires that were cut and the LH tail light wires that were also cut. And, replaced a missing lens and FO rubber boot for the license plate bulb.

Was really hoping that the rear rubber grommet was a 2-piece unit so that I could leave the rest of the wire harness intact and just rethread the LH and RH tail light fiber optic cables. By some miracle, the guys who cut the tail light fiber optic cables missed the license plate FO cable and it works and displays perfect, nice and bright. All of the front FO lights work just fine. Just the two tail lights

Thank you for the links to these other options.

 

Here's an old trick that I have used for many years- but haven't seen somebody else putting a Youtube out on it...yet...

I did it when I needed another hole on the grommet.

Just need-

- A piece of tubing slightly larger than the wire(s)
-Grinder or file
-Drill

Take one end of the pipe and sharpen up the edges on the grinder.

Chuck it up in your drill and carefully-slowly drill into the grommet- obviously being careful not to nick the other wires.

Remove pipe from the drill- run your wire(s) through the pipe and pull the pipe on through when you have the wire about as far as you need them.

Richard

 

I just took a new razor and made a vertical slice halfway through to the center, peeled it off and reused it when I added a new FO harness/

https://keenparts.com/corvette-parts...partnum=560021

All grommets
https://keenparts.com/corvettepartsl...r=1969&submit=