63 under dash wire

[Joe R.]

Re: 63 under dash wire

This is a pic of a 64-67? instrument wiring harness. This thing has black wires with green tracers all over the place BUT this is interesting as there are two black/green wires going to the dimmer switch.
Could the black/green wire in the original pic been pulled from the dimmer switch??
Here the pic.

JRDSCN4098.jpg

[Richard M.]

Re: 63 under dash wire

Joe, I just checked the diagrams again.....The 1963 dimmer switch wiring is different from '64-'67.

1963 those 2 wires are plain Light Green, which go to the headlamps(Hi-Beam I think). Tan is Low beam?

1964+ those 2 wires are Black/Light Green. 1964 Wiring Diagram

Rich

[Rob M.]

Re: 63 under dash wire

Joe, I just checked the diagrams again.....The 1963 dimmer switch wiring is different from '64-'67.

1963 those 2 wires are plain Light Green, which go to the headlamps(Hi-Beam I think). Tan is Low beam?

1964+ those 2 wires are Black/Light Green. 1964 Wiring Diagram

Rich

why not trying to figure out where it ends-up, I mean somewhere the other end of the wire should show up???

[Richard M.]

Re: 63 under dash wire

why not trying to figure out where it ends-up, I mean somewhere the other end of the wire should show up???

Rob, that's what we were trying to get the guys to do but in Brian's case, he doesn't have the car in front of him.......

Monte found that picture in another thread.......

And Norm has the wire in his car and is going to try to trace it more. But it may mean tearing the harness tape off and I wouldn't want to do that if it was my car either.

We need a old harness from a early car that has the mystery wire in it to check more. Joe thought his was one but it appears that it's a '64 harness with the same color wires but on the dimmer plug, not the same wire as "The Mystery Wire".

Rich

[Norm B.]

Re: 63 under dash wire

Found it! Well, I found the other end of it.

Just to make sure I checked and there is continuity between the terminal at the kick panel and the one side of the terminal under the hood.

The second wire at the terminal under the hood appears to have a solid green wire solid green and has continuity to ground.

So now what?

[Joe R.]

Re: 63 under dash wire

Norm,

Looks like you have found the plug that goes to the Back-up lamps!!!!! Yes, a 63 had back-up for about $15.00! Option!

JR

[Monte M.]

Re: 63 under dash wire

Joe,
That is what I suggested quite a while back. I was told it is not for the back-up lights. They even specified which wires were the back-up lights.

So Norm, are you saying that the black wire with green, on one side of that plug is the other end of the mystery wire?
You have checked continuity between the end? And, the other wire on the same plug goes to ground?

Thanks,
M

[Rob M.]

Re: 63 under dash wire

Norm,

Looks like you have found the plug that goes to the Back-up lamps!!!!! Yes, a 63 had back-up for about $15.00! Option!

JR

Why would you backup lamp end up near your wiper motor? should there be an extra extension towards your transmission box for the reverse switch???

[Bob R.]

Re: 63 under dash wire

Rob,
I think there is a short harness that connects at the wiper motor area and drops down to the transmission for the backup lights.

[Norm B.]

Re: 63 under dash wire

Joe,

So Norm, are you saying that the black wire with green, on one side of that plug is the other end of the mystery wire?
You have checked continuity between the end? And, the other wire on the same plug goes to ground?

Yes that is what I am saying. I checked black/green stripe wire between the terminal at the kick panel and the terminal near the wiper motor and there is continuity.

The other wire on the same plug near the wiper switch has no power to it at any position of the ignition switch. It tests out as going to ground when I connect one end of my multimeter to it and the other end to the positive battery terminal, but I have not traced where it physically goes. I have every reason to believe this car has its original wiring so after 50 years who knows? It could also just be grounding out somewhere due to insulation failure.

[Richard M.]

Re: 63 under dash wire

Okay, this is good news. Norm, thanks for delving into your wiring. Your car had factory installed T86 Backup lamps at one time.

Monte, yup you nailed it.

The reason some '63's had this wire, and some did not, is this............There was a different dash harness for cars without T86 backup Lamps. The stock harness is part# 2983971. If you ordered T86, the dash harness was part# 2983972. And guess what, it has that Black/Green wire in it. The connector next to the wiper motor was to connect to the Backup lamp switch harness. The switch mounted at the transmission, and the Green wire was the feed wire coming from the main harness, which is probably tied into the ACC or IGN circuit. It must be spliced in there somewhere.

Also, because new wires had to go to the rear of the car, the Rear harness was different too. It was part# 2983552. Part# 2982644 is the stock non-BU lamp harness.

Below in the AIM Section T86 Sheet 1, it shows our mystery wire and connector. Also see item 30, it's tape that's added to hold the mating connectors together to the large connector for the rear harness wires. So....the rear harness has the mating connector for our mystery wire/connector.

PA020001.jpgPA020002.jpgPA020003.jpgPA020004.jpg

All 1963 wiring diagrams only show stock wiring and do not show optional wiring, like this T86 option.

It appears the mystery is solved.

Rich

[Richard M.]

Re: 63 under dash wire

Yes that is what I am saying. I checked black/green stripe wire between the terminal at the kick panel and the terminal near the wiper motor and there is continuity.

The other wire on the same plug near the wiper switch has no power to it at any position of the ignition switch. It tests out as going to ground when I connect one end of my multimeter to it and the other end to the positive battery terminal, but I have not traced where it physically goes. I have every reason to believe this car has its original wiring so after 50 years who knows? It could also just be grounding out somewhere due to insulation failure.

On the 1967 with stock backup lamps, the BU lamp bulbs are grounded on one side, and the BU lamp switch on the transmission switches +12V via the IGN Pink wire. I'd suspect the same for 1963 T86.

I am not sure if this is the same circuit wiring on the '63, but Norm, you may be seeing ground on the Solid Green wire through the wiring in the IGN circuit(coil, etc). If the '63 is through the IGN circuit, try disconnecting your coil+ wire to see if it changes. Also, pull all of your fuses(one side only) one at a time and see if ground disappears.

Rich

[Norm B.]

Re: 63 under dash wire

OK Richard, I will try what you are suggesting to see if the ground condition changes on that solid green wire sometime over the next couple of days. I have had a couple of wire insulation issues this past summer and this may be another one.

OK, so we have solved the initial mystery but here are a some things that are still bothering me about this wiring;

1. Brian as the originator of this post can you answer a couple of questions? Does this car have back up lights? Did it ever have back up lights? Is it an early car like mine?

2. Assuming that the rear wiring harness is different for back up light equipped cars what color wires would I expect to find on mine going into the inboard rear lights?

3. From what I know of my car I have to assume that back up lights were likely not ordered. I really suspect the car was ordered specifically with 1/4 mile trips in mind since it is an L76 4 speed and originally had a 4:11 rear end. The only other option on the car was the radio. Conversations with owners 2 & 3 and a couple of pictures they provided more or less confirm my suspicions. Why would anyone who ordered a car with this configuration in 1962 have added back up lights? It appears that only about 1.5% of '63's were ordered with back up lights so I am wondering if some early cars had this wire even if it did not have back up lights.

The first picture was sent to me from owner #2 and it is circa 1966. No back up lights are evident. The second picture is from owner #3 who bought it in the early 70's.

[Timothy B.]

Re: 63 under dash wire

I have a November built 63 coupe and I will check the original harness later today for the wire and report back. My car did not have back up lights as best I can tell.

[Norm B.]

Re: 63 under dash wire

Thanks Tim. I was hoping you might jump in here because your car is close to mine on build dates. The outcome has no great impact on my car as it is just a driver but I sure am curious now.