Good day all.
Found some time to work on the 66 today. Still cleaning up some electrical demons from PO.

I have this fat green and red wire coming through the firewall grommet with the wires for the amp meter gauge.
Inside the cab it just dangles not connected to anything and obviously cut from engine bay side.

Can anyone tell me where or what this wire does?

Thanks,
Aaron

 

I recently took apart two of those C5TA-10A665-C harnesses. In order to run some extra wires in one for my Neutral safety switch. Both of them had that green wire in them and it had been cut off and taped over in both of them. I suspect that harness was used in other larger trucks that had some other sensor wired in that our trucks don't have.

 

Green with red should go to voltage regulator. It starts off at fuse box then ignition switch thru firewall. Circuit 904 Rings a bell. Let me look it up

 

All F Series wiring can be found on FaceBook Page
Not high quality scans at this point as the pages are 18" x 12" but it all should be legible.

facebook.com/groups/115882955674725

 

Already have a green and red stripe to the voltage regulator.
I have a green and red stripe from the alt warning light which goes to one of the factory junctions near the horn relay.

Thank you for the link.

Aaron

 

C5TZ-10A665-C .. Wiring Harness-Use with Indicator Lamps, Oil & Amp Gauges / Marked with ID engineering numbers: C5TA-10A665-A or C or E / Obsolete

1965/66 F100/250 2WD & F350; 1966 F100 4WD

 

Complete 1966 F series wiring diagrams there.

 

Me Too!
Seems like we have at least three harnesses here that the green/red wire has been neatly cut out of. And the remains left in the loom. In both of my harnesses that wire would have exited the harness about the middle of the firewall right behind the engine. Could it have been they made a change in the harness and instead of redoing them they just cut the wire out.