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Adapting '70s truck ignition switch to EB

thegreatjustino

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Has anyone ever adapted a '70s double sided key ignition switch to an EB?

I have an EB with no ignition switch after replacing a steering column that had the ignition switch on it.

I just happen to have the ignition switch from a '72 F250 as well as an aftermarket pig tail. Typical crap aftermarket part has six black wires coming off of it instead of trying to match the factory wires.

I'm getting nowhere trying to find a wiring diagram for this switch so I can figure out what the original wire colors were. I'd like to adapt this to the original harness in my '74 but need to know where to splice each of the six wires.

The EB side of the wiring is pretty easy using the colored Sea Biscuit charts, but the F250 side has me scratching my head.
 

cldonley

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Robinson, TX
My '69 had that type of switch in it when I bought it, although I have no idea what year model truck it came from. When I took the switch out the wires were marked with tape and spliced into the original EB wiring harness. Near as I can tell from the wiring diagram, the back of the late model switch was identical to the back of the original (meaning function of the poles) just with different colors on the wires. I will dig it out tomorrow and send a pic if no one else chimes in with better intel. It worked great, except that the PO did a lousy job of fitting it to the dash.
 

toddz69

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Has anyone ever adapted a '70s double sided key ignition switch to an EB?

I have an EB with no ignition switch after replacing a steering column that had the ignition switch on it.

I just happen to have the ignition switch from a '72 F250 as well as an aftermarket pig tail. Typical crap aftermarket part has six black wires coming off of it instead of trying to match the factory wires.

I'm getting nowhere trying to find a wiring diagram for this switch so I can figure out what the original wire colors were. I'd like to adapt this to the original harness in my '74 but need to know where to splice each of the six wires.

The EB side of the wiring is pretty easy using the colored Sea Biscuit charts, but the F250 side has me scratching my head.

My dad did that swap in my Bronco back in the 80s. He felt the stock key was pretty wimpy and had a 77 F250 with the dual-sided key it came with so he swapped it in. I still run it today. Unfortunately I don't have a wiring diagram for you.

Todd Z.
 
OP
OP
thegreatjustino

thegreatjustino

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In the few hours since I've posted this, I've found that the six wires on the back of the switch are Run, Start, Accessory, Battery, and then two proof wires.

Seems to me the run goes to the coil, start goes to the small terminal on the solenoid, accessory goes to the gauge cluster regulator, battery splits and goes to a few different things (positive side of the solenoid, voltage regulator, and alternator), and the two proof wires can be used for the brake imbalance switch.
 

Crush

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Another advantage of this type of keyswitch is that if you have another ford car/truck with the same keyswitch is that you can have one side of the key cut for your bronco and the other side cut for another car. The switch only has one tumbler set. The other side of the key is cut identical so you can put the key in any side up. So you can cut each side for a different behcle
 

toddz69

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I talked to a fellow Bronco club member here in AZ years ago that swapped the later model lock cylinders into the Bronco doors as well so the same key could be used for the doors/ignition.

Todd Z.
 

Steve83

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Memphis, TN, USA, Earth, Milky Way
You didn't say what year your eB is, but this diagram shows the ig.sw. pinout:


https://www.supermotors.net/registry/media/890070_1 (for phone apps)

This shows the later one:


https://www.supermotors.net/registry/media/831772

This shows an eB with an '88 column:


https://www.supermotors.net/registry/media/1022838
...have one side of the key cut for your bronco and the other side cut for another car. The switch only has one tumbler set. The other side of the key is cut identical so you can put the key in any side up. So you can cut each side for a different behcle
That won't work. The tumblers are back&forth; the adjacent tumbler reads the OTHER side of the keycut, so you'd have to mix the 2 cuts across both sides of the key.
 

toddz69

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Can you just change lock cylinders?

Yes. I don't recall if my dad ever owned multiple Fords at the time with these types of ignition switches/lock cylinders on them at one time or another or not, but I do recall him saying it would be pretty cool to have multiple vehicles and only need one key between them.

Todd Z.
 

DirtDonk

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I would definitely do the door locks too if you get the chance.

Paul
 

Crush

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Kind of off topic but is key related. In about 1981 my granfather bought a 76 cadillac eldorado convertible. Fixed a dew things on it and had anreally nice car. In 1986 he thought it would be really cool and nice to order my grandmother a matching 1986 cadillac sexan deville with all the options. The car came in and was a perfect match. By perfect i mean down to the keys. They asked me to go move the 76 one day and i went to their house and grabbed the keys off the keyboard he had. Moved it and left. Well i get a call a couple hours later asking how i moved it. I told them where i got the keys from and they said those are the extra keys for the new car and that they had the keys for the 76. Well ling story short both cars had the exact same keyset. Doors/trunk/glovebox and ignition. Whats the odds on the same man getting two cars 10 years apart with the exact same keyset??
 
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