Topic: Boss 302 unusual wiring

[midlife]

You will find that plug used on all 69 and 70 Mustangs with AC, as that is the lead for the AC clutch.  The question is: what was it used for, if at all, for non-AC cars?  I have two examples from B2's, one of which I know is late 69 production.

[J_Speegle]

You will find that plug used on all 69 and 70 Mustangs with AC, as that is the lead for the AC clutch.  The question is: what was it used for, if at all, for non-AC cars?  I have two examples from B2's, one of which I know is late 69 production.

Yes in looking on non-Boss applications I also found it as a AC connection. At this point I don't think it was used at all for the Boss 302 just like other options when not purchased on other cars the support wiring was included in the standard wire loom and just not connected to anything. Saved on making individual different main looms for all the different possible combinations

[midlife]

Yes in looking on non-Boss applications I also found it as a AC connection. At this point I don't think it was used at all for the Boss 302 just like other options when not purchased on other cars the support wiring was included in the standard wire loom and just not connected to anything. Saved on making individual different main looms for all the different possible combinations

I almost agree with you.  Two things stand out: it WAS connected to something: the RUN-only ignition line instead of the standard AC switch.  In addition, since the heater box was for a non-AC system, the heater extension harness was different than the AC version (the heater boxes differ in where the resistor pack is).  This suggests that Ford knew that there was a reason for using a modified AC underdash harness for Boss cars by having the wiring manufacturer cut the AC line, splice the outgoing line to the ignition switch line, and providing a non-AC heater box extension harness.
The only other thing I can think of would be a hood-mounted tach that would use the RUN-only line to power it.  I don't think B2's ever came from the factory with a hood-mounted tach, though...

[midlife]

Today, while attending Marcus Anghel's open house, there was a concours-level 69 B2, and I talked with the owner.  Sure enough, there was the green wire/black boot normally associated with AC clutch.  I got the owner to show me where that lead went to: the carb anti-stall solenoid.  On a manual transmission car?  Yes!  I didn't think that was possible, but it was.  Of course, an anti-stall solenoid would need a RUN-only line to power it.  So...Ford decided to use an AC harness, cutting the line to the AC clutch and routing it to the ignition switch. 
 In fact, the MPC shows a 69 underdash harness specifically for the B302 with suffixes BC and DC for the underdash harness less tach and BB and BD with tach (mid-year changes). No listings for B2 specific harnesses for 1970, as all 1970's came with leads for the anti-stall solenoid as standard equipment.  But...the green wire is still there on 70 B2's, as evidenced in the top 2 photos that Jeff displayed.
Very interesting...

[specialed]

There was a wire plug used on auto trans cars single wire that lighted up the shifter bezel PRN123 selector.

[midlife]

There was a wire plug used on auto trans cars single wire that lighted up the shifter bezel PRN123 selector.

I was under the impression that no Boss 302's came with automatic transmissions.  Is this incorrect?

[carlite65]

your impression is correct.....auto would defeat the performance style/image.

[specialed]

same wiring harness ford never  made auto and manual separate wiring harness as the 4 post square plug is the same but the plug in wiring harness to trans are different but auto uses a separate  single wire that plugs into 1 of them plugs that routes to auto shifter bezel bulb  to light it up.