In my quest to at least get this thing driveable while I work on other parts, I pulled all the extra wiring the previous owner(s) installed (and of course, it was all twisted/taped...not a single proper splice anywhere, lol). Of course, I now have more issues after - namely not being sure which wire goes to the ignition switch for switch power to the rest of the circuits. Yes, a PO did cut the connector, and replaced the switch with a universal generic switch.

This must be one of the areas that the '65 and '66 differ, because the diagrams I have for a '66 aren't even remotely close to what I have. I'm going to order the full set of manuals, but this is the only part that keeps me from driving it in the mean time.

Does anyone have a good diagram that they could tell me what colors of the wires are going to the switch?

 

On my '65 F250, the ignition switch is wired as follows.
On the stem of the switch there is a Black/Green connected. This runs to a factory splice that has the feeds for the warning light, voltage reg, and another Black/Green going to the fuse box.
On the screw connection on the back of the ignition switch, there should be a Red, which runs to the resistor wire that is connected to the main engine harness, and a Yellow is connected to the switch, which is the power coming from a factory splice that has a Black/Orange from the headlamp switch, a Black/Yellow which is the feed from the battery, and a Red going to the fuse box.

Hope this helps

 

The ignition switch (C3AZ-11572-A replaced COAB-11572-A) is the same for all 1961/66 series' of trucks (except P Series), Econolines, 1966 Bronco's and misc 1960/66 Passenger Cars.

But...in 1967, Ford replaced this switch with another (C7UZ-11572-A) that has an extra connector. FTE member Confederate Diesel has the wiring schematic for this replaced switch.

This C7UZ switch was factory installed in 1967 Econolines and 1967/77 Bronco's.

 

Yes, this was a BIG help, thank you Knowing what circuits those wires are running tells me exactly what I need to place them on the proper terminals on the replacement switch.


The switch might be the same, but the wiring colors are not, at least not according to the diagram I have from Mitchell. The colors this diagram claims goes into the various parts is nothing like what I see in the truck, and there's several areas where even the number of wires shown on a connector doesn't jive with what I have. Also, as I stated before, I don't have the original switch, it's been replaced by a universal generic switch, nor do I have the factory connector, so getting a factory switch would be of little use to me.

However, what F250GH says is on his truck matches what I see on mine.

 

Which ignition switch does F250GH have on his 1965 F250 Good Humor Ice Cream truck?

Is it the C3AZ-11572-A original that was obsoleted in 1967? Or is it the 1967 (C7UZ-11572-A) switch that replaced the original?

 

Thanks again, F250GH, I now have a running truck, with almost all gauges and dash lights functional. The oil light isn't coming on with the key on/engine off, although there is a mechanical oil pressure gauge in it..well, was- I accidentally broke the line, and now have oil soaked **** carpet, lol. I'll be replacing it with an electrical, but I'd also like to get the factory idiot light working as well (I'm overly **** about that kind of stuff, lol)

I also don't yet have the temp gauge working, although I'm not 100% sure I have the right wires going to it. I didn't pay attention to what I pulled off the aftermarket gauge that was installed, so I took a guess. I'll trace the wires out tomorrow to make sure I have the right ones, and verify the sender is good.

 

Use this as a guide to determine if you have good continuity at the firewall main disconnects. http://www.tocmp.com/tOCMP/wiring/19...964_02_gif.htm
Use an ohms meter or volt meter is useful to check each circuit. Some of the colors might be different from what you have, but the main disconnects will point you in the right direction on determining what goes where. Did you remove the dash cluster and check all of the connections and replace the lamp bulbs?