#1  
Old 09-12-2020, 08:38 PM
bluejudge bluejudge is offline
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Default Fiber Optic Wire

Does anyone know the correct length for the fiber optic wire that goes to the ashtray, the one I have in my 69 GTO is about 28 inches long and the new one I purchased from Ames is 20 inches. I called and asked about it, they referred me to call M&H and when I spoke to them they said 20 inches was from the GM blueprints . It does not make sense to me because the one that is 20 inches long will not reach from the top light socket to the ashtray. Can anyone tell me what the correct length is? Thanks, Marc

  #2  
Old 09-12-2020, 09:48 PM
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64-3Deuces 64-3Deuces is offline
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The 5/74 MPC lists the following: Panel Light Fiber Optic, 68-72 All A/F body, #6293310, guide ash tray light, 20” single wire.

However, GM makes modifications and running changes during the model year and maybe it was determined that a 28” cable was needed. M&H could be working off an original blueprint, and the MPC never updated and still reflects the original 20” spec. Not familiar with the 69 dash cluster but is it possible that the socket the cable attaches to should be in a lower position, though it has a 28” cable for a reason.

  #3  
Old 09-12-2020, 11:25 PM
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20" I think is the 68 lighted ignition switch length

I wont be able to check till monday and compare

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Old 09-13-2020, 10:19 AM
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Quote:
Originally Posted by Scott Thelander View Post
20" I think is the 68 lighted ignition switch length

I wont be able to check till monday and compare
The MPC shows the optic cable length as 20" as I show in post #2. Hopefully your comparison will clear up the reason the OP appears to have a 28" cable.

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Old 09-15-2020, 06:51 AM
bluejudge bluejudge is offline
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I can’t see how this cable should be 20”. I will not reach the top light socket on the top left of the circuit board if you are looking from behind the dash, unless I am doing something wrong and that is why I am asking. I would have thought this subject would have come up before, I am sure I am not the first person to order a new fiber optic wire. That is why I want to see if It was something I was doing wrong. Thanks, Marc.

  #6  
Old 09-15-2020, 08:11 PM
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Quote:
Originally Posted by bluejudge View Post
I can’t see how this cable should be 20”. I will not reach the top light socket on the top left of the circuit board if you are looking from behind the dash, unless I am doing something wrong and that is why I am asking. I would have thought this subject would have come up before, I am sure I am not the first person to order a new fiber optic wire. That is why I want to see if It was something I was doing wrong. Thanks, Marc.
As I stated in my previous post not familiar with the 69 dash so I could only provide what the part book says which backs up the M&H reply, and my thoughts on why the difference. The wiring diagram in my GM service manual for the 64 shows the wire for the heater blower as orange, yet the wire in my OEM harness is black, and every 64 I've seen has the black wire. Reason?????

Hopefully Scott (post #3) can provide an answer.

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Old 09-15-2020, 10:50 PM
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Going over the '69 assembly manual there was a late model year change in the routing of the fiber optic cable (#8 in the drawing and parts listing) with the addition of a retaining clip.
However the fiber optic part number remained the same as before which is 20".

EARLY



LATE

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Old 09-16-2020, 08:25 AM
bluejudge bluejudge is offline
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Quote:
Originally Posted by OG68 View Post
Going over the '69 assembly manual there was a late model year change in the routing of the fiber optic cable (#8 in the drawing and parts listing) with the addition of a retaining clip.
However the fiber optic part number remained the same as before which is 20".

EARLY



LATE

Thanks, mine would be the early version. The car was built in December 1968. Thanks, Marc.

  #9  
Old 09-16-2020, 12:14 AM
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20" 68 69
16 on 68 ignition light
28" is grand prix .... I put 69 but forgot g prix on the tape
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  #10  
Old 09-16-2020, 08:30 AM
bluejudge bluejudge is offline
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Quote:
Originally Posted by Scott Thelander View Post
20" 68 69
16 on 68 ignition light
28" is grand prix .... I put 69 but forgot g prix on the tape
Thanks Scott for taking the time and sending this detailed picture. I guess I am doing something wrong somewhere. I put the dash back in with the 28” wire for now and kept the 20” on the side for now. One problem at a time. I have to hook everything back up and see if the original problem is fixed. I think the wire to the coil was no good and the car would not stay running. Thanks, Marc.

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