Steve: I forgot that there were differences between the 65 and 66 wiring harnesses. I would suggest that you look at the wiring diagrams for both years to make sure of what
you can and cannot do, due to compatibility issues. When I saw the wire you were referencing, I just looked at my car (a 1966) to see what hooked up to it.
Well, I wonder what the difference is between a 1965-with-gauges alt harness and a 1966 alt harness. They both look exactly the same and have the same number of wires, and even the wire colors are the same. Check it out.
Here's a 1965-with-gauges alternator harness:
and here is the 1966 alt harness:
I don't see a difference, but there must be one since there is a different harness for each year. Does anyone know what the difference in the harness is?
Like I said, I haven't found a wiring diagram for 65 with gauges. Comparing the standard 65 to 66, the underdash wiring is also different but I would imagine this is addressed by the "with gauges" version.
Will have to keep searching for the 65 with gauges diagram...
Steve: I forgot that there were differences between the 65 and 66 wiring harnesses. I would suggest that you look at the wiring diagrams for both years to make sure of what
you can and cannot do, due to compatibility issues. When I saw the wire you were referencing, I just looked at my car (a 1966) to see what hooked up to it.
John
Hi John, I think you are 100% correct. The wires I have in my car are a mixup of 1965 and 1966. The gauge feed is for a 1966 and the headlamp harness is for a 1965 (the underdash loom is 1966 too). I'm thinking I should have bought all 1966 wires so that they would all go together and I wouldn't be having these stray wires.
I looked at the 1966 headlamp harness and it has the yellow wire with the male bullet connector. Common sense tells me that is the wire I'm missing. Do you know what the purpose of the yellow wire is?
The trouble is - I don't know what else might be different...
Yes, I looked at those images too. I figure that the 1965 & 1966 Stangs were so similar, that if I convert to all 1966 wiring I should be OK. Looks like the same voltage regulator was used all the way to 1967, and the alternator is the same....don't know what else might be different.
Thanks for all the input. I just hope I can exchange the 1965 headlamp harness with CJPonyParts for the 1966.
Steve: I have to agree, I don't see a difference in the alternator harness you show pictures of. But the NPD catalog does list different part numbers for the different alternator harnesses for the 65 and 66 model years. From what I can see from my 66 wiring schematics, and looking at my car, that yellow wire is part of the 66 amp meter
circuit.
Steve: I have to agree, I don't see a difference in the alternator harness you show pictures of. But the NPD catalog does list different part numbers for the different alternator harnesses for the 65 and 66 model years. From what I can see from my 66 wiring schematics, and looking at my car, that yellow wire is part of the 66 amp meter
circuit.
John
If I get the 1966 Headlight harness, it will plug into the connection provided. This seems to be the most logical solution. Don't you agree?
The yellow wire must come from the voltage regulator and plug into the wire by the solenoid. What I don't want to happen is for my nostrils to be assaulted by the smell of burning rubber when I hook up the battery.
Steve: The yellow wire is tapped into the yellow-black wire that comes from the alternator harness. That yellow wire, as we have discussed earlier, plugs into the other yellow wire near the solenoid. The yellow wire then runs back through the firewall to the amp meter and returns, to complete the circuit, as a red wire, that connect to the battery side of the solenoid.
As far as getting a 1966 headlight feed harness, I'm not sure if it would work. Others more versed in this may be able to help. The yellow wire that we have been talking about is tapped into the yellow-black wire, in the alternator circuit, in the headlight harness, after the point in which the alternator harness plugs into the headlight harness. That's why you don't see the yellow wire in the alternator wiring harness pigtail that is attached to the alternator itself, you just see the yellow-black wire. I know, it sounds confusing.
My concern with the 66 headlight harness would be with where it connects at the firewall with the 65 underdash harness. I don't know if the wires are the same color and purpose on both sides of the plug connection. Again, others may know.
Steve: The yellow wire is tapped into the yellow-black wire that comes from the alternator harness. That yellow wire, as we have discussed earlier, plugs into the other yellow wire near the solenoid. The yellow wire then runs back through the firewall to the amp meter and returns, to complete the circuit, as a red wire, that connect to the battery side of the solenoid.
As far as getting a 1966 headlight feed harness, I'm not sure if it would work. Others more versed in this may be able to help. The yellow wire that we have been talking about is tapped into the yellow-black wire, in the alternator circuit, in the headlight harness, after the point in which the alternator harness plugs into the headlight harness. That's why you don't see the yellow wire in the alternator wiring harness pigtail that is attached to the alternator itself, you just see the yellow-black wire. I know, it sounds confusing.
My concern with the 66 headlight harness would be with where it connects at the firewall with the 65 underdash harness. I don't know if the wires are the same color and purpose on both sides of the plug connection. Again, others may know.
John
Hi John, my underdash harness is a new 1966 harness (I'm converting to gauges). That's why I was thinking that I should have gone with all 1966 wiring when I bought the various harnesses for my project.
With that said, the 1966 headlight harness, the 1966 gauge harness, the 1966 alternator harness and the 1966 underdash loom should all work together, no loose wires (in theory), right?
I already have the 1966 underdash and 1966 gauge harnesses. i just need the 1966 headlamp and the 1966 alternator harnesses. I hope.
If you change to the 66 headlight harness you should be good to go!
My concern was your underdash harness but you have already changed to 66.
Thanks for your help Frank. Hopefully when I swap harnesses everything will plug together without issue. I was so close to putting a battery to the car and checking all of the electrical. Oh well, a couple more days delay won't matter too much. If everything goes well, I'll be starting the engine for the first time since I rebuilt it (and that was years ago).
To beat the dead horse a bit, that yellow wire is the completion of the circuit to the ammeter... I know becasue in my 66, I eliminated the wire that it plugged into (switching to 3g alt) and subsequently used that yellow feed as well as the red ammeter feed to be used to feed other modern gauges... you can simply splice into the yellow w/black stripe wire on the alt harness to compelte the circuit if you are running ammeter,,, but I recommend you switching to volt meter if possible.
JMTC
__________________ 1966 Mustang GT RestoMod Project: 307c.i.d.,Holly 600 4brrl, TrickFlow Heads, Power Disc Brakes, Integral Power & Tilt Steering, AOD, 9" 3.50 posi rear end & a bunch of other stuff.
Project start date 1999. Completion date... fagidaboudit!
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