Topic: Late 69 B2 Factory Wiring

[midlife]

I've done several B2 underdash harnesses, but the latest one is a headscratcher.  It is a 69 standard dash with A/C, but the A/C wiring is all screwed up in original factory condition.  One of the lines to/from the de-icing switch was terminated inside the factory taped harness, so that line when nowhere.  The line going to the A/C clutch was tied into the green/red wire at the ignition with a factory OEM splice, meaning that this line was always hot whenever the key was in the RUN position.  Normally, this line goes to the de-icer that was found to be cut off inside the harness.  The customer says his build sheet says no A/C, so maybe that line was for a electric choke?  The plug just beyond the firewall is exactly like all other A/C cars I've seen.

My question is: did a late 69 Boss302 have an electric choke or any emission controls (or antistall dashpot)?  The customer says it is a very late 69 build and I know that the 70's did use the emissions control line for the carb.  The customer says he has the original carb and the car has a manual choke.  Very puzzling...

[jmlay]

A Boss 302 does not have A/C... There is an anti stall dashpot.

[midlife]

Bless you!  That explains that...Ford took an A/C harness, cut one line, left the rest alone, and tied that one line to the RUN signal from the ignition switch.  Probably quicker and cheaper than redesigning a whole new system...cheap bastids!

[jmlay]

Are the part number tags still on the harness? I was not aware the Boss harness being any different than any other for the year. But then again I have never had cause to look into it.

[midlife]

The part number that I got was: C9ZB-14401-BC.

Here's what I think is going on.  The B2 early run may have had a problem with not having an anti-stall dashpot, maybe due to emissions.  When Ford realized what the fix would be late in the model year (a solenoid dashpot on the carb, powered up by a signal that is only on when the car is running), they had two choices: redesign the wiring harness, or perform a quick fix.  Since B2's (apparently) never came with AC, one could take a standard Mustang AC harness, cut the line from the de-icer switch to the AC clutch plug and connect the line into the ignition coil run line...a quick and dirty trick.  For 1970, Ford instituted a slightly better design by routing the same signal though the fuse box (just in case) and added a dedicated plug (blue wire, white female bullet) for the dashpot solenoid.