Richard : I wasn't going to start this thread until I had a little more information, but since you did, I'll pass on what I have found out so far.
For several years, I have been helping a friend, and fellow CMF member in California, with his 67 Mustang Coupe. In particular, he had questions in regard to original Ford Accessories and Options that were available for his 67, This included what all was included with them, how they were installed, instruction sheets, etc.
His car, for which he has his Marti Report, is a 67 Coupe, built in San Jose on September 30, 1966 (6 days ahead of schedule). It is a non-GT, 289 C Code, with C4 Automatic, Power Disc Brakes, Power Steering, Select-Aire, Tinted Glass, and AM Radio.
Recently, he told me that he'd like to add the Hood Mounted Turn Signal Hood to his car, and asked if that would be a problem. I told him that it was part of the Exterior Decor Option, and "to be correct", the Wheel Lip Moldings, Trunk Moldings and Pop Open Gas Cap should also be added. He wanted to start with just the Hood. I told him that once he had the correct Hood, and Turn Signal Harness, it was basically just "Plug 'n Play", connecting the harness connector to the one located outboard of the Master Cylinder. I sent him a copy of the Exterior Lighting, Turn Signal Wiring Diagram from the 1967 Shop Manual (printed March of 1967), with the connector circled, as well as an actual picture of the connector (first two pictures attached).
When he got back to me he noted that he had purchased a 67 Deluxe Hood that was complete with the lights, grills and Hood Harness, and most importantly to him, was the same color as his car so that he wouldn't have to have it repainted. From reading the 5 page thread that was started here in 2012 on the Hood Mounted Turn Signals, he knew that the Hood was not really correct for his early car, as it had the too large holes, but he was not as concerned about that as the fact that it would not have to be repainted. He also knew from reading the thread, that the Turn Signal Harness was not correct as it had the plastic light socket housings, and not the metal ones that the early ones should have,
The next time he got back to me, a few days later, he noted that he and his Son had looked all around the Master Cylinder for the connector, or cut wires where it may have been, but there was no evidence of the connector. I then thought that possibly, the early cars had a different Headlight-Turn Signal Harness. I Pulled out my Preliminary Shop Manual (Printed in August of 1966), and sure enough, the wiring diagram in it (copy attached) shows no "extra" connector for the "RPO Turn Signals" as noted in the regular Shop Manual. I then went a little further, and looked in the 1960-68 MPC for 1967 Mustang Headlight Harnesses. To my surprise, there were actually four different headlight harnesses listed for non-GT's and without the Tachometer Option (copy attached). One of the four is noted :Before 10/7/66", which gives the possibility that it may not have had the connector for the Hood Mounted Turn Signals. I say possibility because we do know from previous comments, that cars built in November, December, and January (and probably later), all have the connector.
I passed this information on to my friend, and told him that there must have been an "auxilliary" harness that was used in addition to the Headlight Harness, when the Exterior Decor Option was present, but I did not know that for a fact.
When he next got back to me, he noted that he had contacted a Mustang Restoration Shop about an hour from his home, that had been restoring Mustangs for over 35 years. He said that the Owner told him that he had the auxilliary harness that he needed, and said it was from an early October 1966
Mustang. The Owner told him that the harness was used if either, or both the GT Option (Fog Lights), or Exterior Decor Option (Hood Mounted Turn Signals) were ordered. [as an aside here, after seeing the example that Jeff Posted, where there does not appear wires that continue on to the Fog Lights, I'd say that there is a good possibility that there were 3 auxilliary harnesses that were used ; one if the GT was ordered without the Exterior Decor Group, one if the Exterior Decor Group was ordered for a non-GT, and one if both the GT Option and Exterior Decor Option were ordered, which is the one that the Shop Owner was offering to my friend]. My friend purchased the harness that he was offered by the Shop Owner (picture attached).
I told my friend that all we needed now was to know how, and where the under dash connections were made. My friend contacted the Shop Owner again and asked that question, and the Owner gave him a sketch for making a double three connector "jumper" (as he called it), and mentioned getting an aftermarket under dash harness. I don't see any reason for another under dash harness, as the 1960-68 MPC shows that only one under dash harness was used from the beginning of production until January of 1967. While I can of course tell him how to make connections more easily, and a lot less expensive in order to make the Hood Mounted Turn Signals function, I'd really like to know how Ford did it at the Factory. My guess would be something like a 2 x 4, female bullet pigtail.
Of course, the only way we'll know for sure (and the whole purpose of this lengthy "dissertation", is to get feedback from Owners of August through early October Mustangs, with known Factory Exterior Decor Options. Hopefully we'll get some so we all can "be in the know".
Bob
