Topic: 66 dash wiring

[Herman]

While I was recently replacing the fog light switch in our Oct 65 built get convertible.  I am across a couple of orange and a grey wire which aren't connected to anything.  They are all female & l couldn't see or find anything they connect too.   Any help would be greatly appreciate.

Herman

[jwc66k]

Herman,
 Check your windshield washer circuits. There's an orange wire in that circuit. And get a copy of the 1966 Mustang Electrical Assembly manual, plus the other three available 66 manuals. They will answer most questions.
Jim

[Herman]

Hi Jim

Thanks for the guidance on which manuals to use. However the wipers are all contacted and working fine without any issues.  These wires are loose and don't appear to be needed. 

In addition, when replacing the Fog light switch the connectors into the wiring loom are different in that they are two wire connectors (1x balck & 1x yellow) instead of three (1x balck, 1x yellow & 1x black with red strip).  Please note the wiring appears to be original.   

Herman

[midlife]

Hi Jim

Thanks for the guidance on which manuals to use. However the wipers are all contacted and working fine without any issues.  These wires are loose and don't appear to be needed. 

In addition, when replacing the Fog light switch the connectors into the wiring loom are different in that they are two wire connectors (1x balck & 1x yellow) instead of three (1x balck, 1x yellow & 1x black with red strip).  Please note the wiring appears to be original.   

Herman

I believe I can answer both of your questions.  The extra wires are leads from the emergency flasher harness, and they are not used in any Mustang application.  I suspect the e-flasher harness was used in other Ford models and simply taken and used for the Mustang in 1965 and 1966.

As for the wiring differences, you are describing the tail-light connectors.  In 1966, there was an early and a late variant (a third variant for 1965!).  Looking at the tail-light connector from the underdash harness:
1965: yellow/white and black are female, two pin plug
Early 1966: yellow/white changed to male, black is female, two pin plug
Late 1966: three pin plug (backup lights now integral) - male yellow/white, black female, black/red female.

Oh...so much fun with mid-year changes.

[Herman]

Thanks Midlife, I really appreicate the help and might explain the 65 wiper switch being used for a two speed wiper. 

Do you know were I may be able to source the early 1966 variant wiring from as I can't see it a major parts supplier?

Early 1966: yellow/white changed to male, black is female, two pin plug

[midlife]

I have many used harnesses of all of these variants in stock which can be refurbished, but not to concours levels. 

Website is http://midlife66.com/harnesses

[slk25]

I am stymied and need some assistance.
I am trying to get the windshield washer operational on my March San Jose 66 Mustang fastback with single speed wipers and windshield washer.
I have done the following without success.
Replaced defective pump, old unit did not function when a 12v jumper was connected to the pump directly.
I have checked the continuity of the wire to the pump and the switch, when the switch is pulled the resistance goes to zero.
The feed wire is connected to a three wire plug shown in the attached pic.
I can find no reference to a three hole female plug in my wiring diagram.
Is this something a PO hacked in and lost the switched power for the switch?

[midlife]

Need a much bigger picture, my friend...can't see squat.

The three pin female plug can be used for early 66's; in late 66's there was a specific line coming from the fuse box near the rear tail light plugs specifically for the washer pump.  Remember: on a single speed wiper switch, there are two unused spade leads.  Both are for the washer pump.  One is an innie and the other is an outie.  It doesn't matter which spade lead you plug into, as it is a simple switch.

[slk25]

sorry Mid, here is a bigger version.
The white wire that is loose feeds the washer switch.
The black wire that feeds the triple plug disappears behind the cardboard shield for the wiper mechanism.

[midlife]

yellow three prong plug is an OEM feature that routes directly from the fuse box (ACC) and provides power to the back up lights, radio, and other accessories.  Nothing hacked on your car that I can tell.

[sgl66]

As for the wiring differences, you are describing the tail-light connectors.  In 1966, there was an early and a late variant (a third variant for 1965!).  Looking at the tail-light connector from the underdash harness:
1965: yellow/white and black are female, two pin plug
Early 1966: yellow/white changed to male, black is female, two pin plug


Oh...so much fun with mid-year changes.

Were there mid-year changes to what connected to the 10 amp circuit breaker? My car has the blue/black from the fog light switch connected to the Aux side and according to the 66 wiring diagram I have, a black/yellow should connect to the Bat side. Not only is it not connected in mine but I don't see a black/yellow coming through the firewall. Grabbed a pic of harness part # if that helps. Should I be looking somewhere else?

Fog lights work fine

[midlife]

Never seen a black/yellow wire for the fog lamp circuit breaker: ever!  It is light blue/black on both sides.  It is spliced into the main battery line, which is black/yellow, however.

Those mid-year changes of tail-light wiring are related (in time) to the changes of the e-flasher wiring, fuse box change, backup light wiring only. 

[sgl66]

Thanks midlife

FWIW, this is an example of the wiring diagram referencing black/yellow http://www.kkpony.com/images/66external-wiring-diagram.jpg

Lights works fine and all connections look unmolested. The switch must be receiving power through the black wire but I don't see any splices. Something to look at on a rainy weekend

[midlife]

Thanks midlife

FWIW, this is an example of the wiring diagram referencing black/yellow http://www.kkpony.com/images/66external-wiring-diagram.jpg

Lights works fine and all connections look unmolested. The switch must be receiving power through the black wire but I don't see any splices. Something to look at on a rainy weekend

That diagram is dead wrong.  Yes, that line is OEM spliced into a black/yellow wire, but the wire is a blue/black.  The black wire you speak of goes to the headlight switch connector so that it ties into the rear running lights.

[sgl66]

That diagram is dead wrong.  Yes, that line is OEM spliced into a black/yellow wire, but the wire is a blue/black.  The black wire you speak of goes to the headlight switch connector so that it ties into the rear running lights.

Thanks midlife!

Sure helps when you are looking for the right colors. I found the correct factory wire exiting the harness with 2 green/red wires for the brake light switch. Also contacted the PO who informed me he removed the wire after leaving the lights on one too many times and killing his battery and chose to rely on power from main light switch instead.