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View Full Version : Gen 3 Wire Harness question.... what are these for?



mkassab
07-09-2023, 09:22 AM
OK... the wire harness that goes to the Mass Air Flow sensor has 3 additional plugs, 1) C132 Ambient Air Temp Sensor, 2) C400 Intercooler and 3) C102A Alternator with 3 wires (red, blue and violet). The C400 is cut and removed per the FF Gen 3 Coyote manual. The same manual makes no ref for the C132 and C102A connectors.

The Factory Five manual only connects two wires to the Alternator... i.e., the heavy red charging wire to the alternator's charge lug and the brown Ignition wire to the 4 wire pig tail (White/IGN wire). In my case, the 4 wire pig tail as you look at it is, 1) top left, Computer Blue wire, 2) top right Frequency Black wire, 3) bottom left, Ignition White wire and 4) the bottom right Lamps Red wire. The FF manual only has the white Ignition wire connect to the brown Ignition Wire in the FF "Alt" wire harness.

I have Two Questions:

1. Now, back to the Coyote harness and in particular the C102A Alt wire. No manual (FF or Ford) state how to connect the C102A 3 wire plug? Any help would be much appreciated.

2. Also, no mention of the C132 Ambient Air temp plug.... where, if any, does it connect to?

Here's a pic of the two plug in question:

https://thefactoryfiveforum.com/attachment.php?attachmentid=187014&d=1688912132

Thanks Mark

Mastertech5
07-09-2023, 09:41 AM
Not sure about the alt. plug but the ambient air plug would go to a sensor in the front of the radiator somewhere to give the factory AC and/or an outside temp display on the dash a reading to use. Not required. I believe the extra alt. wires are for Ford factory computer control of the alt output. The computer will vary the output as required to help save on load to the engine to save on fuel mileage. Someone with more knowledge of Ford systems could be of more help.

Indy Shu
07-09-2023, 10:21 AM
Mark,
The alternator wire plug directly into the back of the alternator. The AAT wires are not used and you can trim them back as far as you’d like.

edwardb
07-09-2023, 05:18 PM
Confirming the C132 Ambient Air Temp Sensor plug isn't used with the crate motor. You can cut if off or just tie out of the way.

The C102A Alternator plug goes into the Ford Performance 5.0 Alternator Kit M-8600-M50BALT used with Roadster and Coupe Coyote installations. For the Hot Rod and Truck, you can't use the standard Coyote alternator in the stock location, right? No space. So the manual shows an alternate alternator installed in a different location. As I understand it, a one-wire alternator so wouldn't use the Ford G6 version connection. For this one you can also cut if off or just tie out of the way.

The only connection required to the alternator will be the large red +12V cable from the Ron Francis harness. The smaller brown alternator wire isn't used. Also can be cut off, removed completely (it goes all the way back to the ignition switch), or just tied out of the way.