So the basic idea is this: You want to use a double pole double throw relay. You'd then need to choose where to tie into the factory wiring. To do this the right way, you would then buy an OEM male and female plug end for an OEM plug connection. You would disconnect the OEM plug and install your interrupt circuit in the middle. Most likely - depending on where you put it - you would solder in most of the wires so they are just a direct jump through to the other side of the plug. The only 2 wires you want to interrupt are the up and down buttons.
So, now we imagine you've got the up and down buttons isolated. The next step is to use the double pole double throw relay. You could also use 2 separate relays, but this is cleaner. What you need then is to wire the hot side of the wire you've interrupted to the common pole of the relay on each side. So "Up" to com1 and "down" to com2. Then you need the other side of the OEM wiring that will continue the normal signal - the other part of the wire you've tapped into - wired into the NC pole on each respective side. That stands for Normally Closed. The default position is to operate normally by passing the signal through.
You will need a toggle switch for on/off of the interrupt system. This will be wired to the coil terminal ends. So ground to coil terminal 1. Coil Terminal 2 to your switch. Switch to fuse to 12v power supply. The result is - turn on the switch, the relay throws.
The NO "Normally Open" post during the default state will do nothing. You roll you window up/down and the window goes up down. BUT when you throw the relay via the toggle switch it will now open the circuit that would have been normally closed (it disconnects the circuit to the window) and closes the circuit from com1 and com2 to NO1 and NO2. Those are now live with the signal from the window switch. You would then wire from NO1 and NO2 to your relays that control your winch in/out functions.
Hope that makes sense.
It's not worth the effort when a wireless relay is $15 on Amazon. But that's how I would go about doing it.
I do use a system like this on my FJ40 because it has no key for ignition. It's just a set of switches on the dash. I use a special circuit I designed as an ignition interrupt so that you must have a couple dash switches fan/lights etc. in the correct position before the ignition circuit will function. Otherwise they just act as pass through. If you don't get the sequence correct it will short a fuseable link at the distributor. If you aren't really damned handy with cars or 100 years old you wouldn't know what a fuseable link even is. And you sure as heck won't figure out how to make it run no matter how you try to hotwire it. It's a low tech theft deterrent. Works essentially on the same principle.
The relays are about $5. The biggest cost will be the OEM plug ends.
