I need to remove the ignition switch from my '78 F-250 P/U and need help with the secret to releasing the individual spade connectors on the wiring. I've poked and pulled with zero luck. And in case things go badly, does anyone have a source of a pigtail for the '78 model switch? NPD & LMC have 73-76 pigtails as does RockAuto, but I can't find one for the '78.
There are generally two types of removable crimp terminals used in Ford wiring harnesses:
(1) Spade terminals with clips; the access is on the front. You must hold the crimp terminal in place in the housing from the back, while pushing the clip down from the front. The wire then slides out. You'll have to bend it back in place before reinstalling.
(2) Block spade terminals, which are larger. They are held in place by a tab in the pigtail itself. These are removed by bending the plastic tab from the back, and sliding the wire out. These are much easier to deal with.
It has been a while, so I can't remember which. If each connector has a small keyway on the front of the pigtail above the center of where the spade terminal from the switch would insert, it's the first type. If not, it's the second type.
In either case, you have to disconnect the switch first; you cannot remove the individual wires with the switch connected. You do not have to remove the individual connectors first to remove the switch, otherwise it would be a chicken and egg problem. If all you need to do is replace the ignition switch, you don't need to worry about the pigtail itself unless it's burnt or damaged in some way. Access is tight, but the pigtail does not need to be disassembled. I have not seen the pigtail sold for 78 models.
The problem was in my switch so when I finally got the connector off, I did not have to replace individual wires in the connector. One was loose and did come out. They seem to be anchored by a protrusion inside of the socket in the connector that mates up with a hole in the side of the female spade connector inserted in that socket. I have photos so if you want to e-mail me at firstname.lastname@example.org, I can give you an idea of what the parts look like.
There is a keyway on the front of the black plastic connector that runs along one side of the inserted female spade connector. One long side of the rectangular cross section of the female spade connector has a square hole and this appears to be the "lock" with the molded protrusion inside of the hole in the black plastic connector. Again, a photo may be worth a thousand words.
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