Topic: 70 Convenience Group ?

[rayms69]

mine is the original underdash harness, black/yellow can easily be connected and looks correct if it was connected, I will have to look at the headlight side, im sure its correct according to Mr.Bill, im not sure if it doesn't dead end at the fuse panel....isn't this black/yellow line a ground, there is a black/yellow wire grounded at the lower dash on drivers side of the instrument bezel. Im gonna connect all my lights to see if they are all working properly this weekend. My headlight harness has 10 wires, no black/yellow, so it terminates at fuse box on mine, which was built after 10-15-69, prior to that date there was 11 wires with black/yellow one. I read that on vintage mustang forums and from talking to Bill when I was ordering a replacement for the weatherbeaten original, which wasn't correct anyways, someone put a no sportlamp version on it for a time.

[midlife]

Black/yellow is NOT a ground!!!!  Only black wires are grounds.

[rayms69]

I will have to look at it again then, this is the ground I was referring to

[70Mach]

I just looked at both of my old harnesses, car is Metuchen 11/20/69.  It has the black/yellow wire in the underdash harness.  It did not have it in the underhood harness and it is a 10 wire harness.  In this setup the black/yellow wire was not used in the underdash harness because all of the park lights were powered by the brown wire.  (And I unknowingly just changed my car to an earlier style because I didn't take the time to compare the number of wires in my old harness to the new harness before I installed it).

When the black/yellow wire was used (11 wire underhood harness) it was the power wire to the front valance park lights only.  All the other park lights were on the brown wire circuit.  When the park lights or lights were turned on and the sports lamps were off the valance park lights were on.  Then when the sport lamps were turned on, the front valance park lights went off. 

When they went to the 10 wire underhood harness all of the park lights are on the brown wire circuit and the front valance park lights stay on when the sport lamps are turned on.   

That's my thoughts on how it works.  I'm wondering if they didn't change it to get all park lights on one circuit.