It depends on the power location, and the type of switch. And really, the switch location too.
If power is in the rear, and if you use relays in the rear, you could do it with just two wires and your Sienna switch -- one for each relay coil (and ground to truck). And, those wires would be small gauge, since they'd be handling minimal current. That is sort of what I'll be doing.
If power is in the rear, but you want to avoid relays, then you'd need the larger switch, and 4 wires to run from front to rear, and the wires would need to be a little thicker. This would be the most inefficient method, due to the long run from back to front to back again, for 4 wires. Wouldn't be my first choice.
If, however, you want only two wires, and you use power up front near the switch, and you're willing to use the larger switch, then you could also use just two wires. They'd still need to be a little larger gauge, but not as bad ad option#2.
If you do want to use power in the rear, your solution will be simpler if you install the switch in the rear too. Then, no wires to run, as long as you have a power and ground available. That would be the simplest solution, plus you wouldn't need to worry about finding a switch that matches the rest, since there are no other switches back there.
Fwiw, make sure fuses are used. It's important that fuses are installed such that:
a) as close to power source as possible
b) be smallest necessary to handle load, and def *less* than the power handling of any wiring being used. I plan to use approx 2amp fuse for the motors. Even with, say, 20 gauge wire running from front to back, the wire should be able to handle a short and allow the fuse to blow before burning my gx to the ground. I'll have to doublecheck the charts to verify the value, but regardless, this project will be fused.
Constant power or not, does not really impact the solution. Mine will be connected to ignition power like the rest of the windows -- just personal preference. I want to avoid malfunctions causing windows to accidentally open/close when I'm not in the vehicle, or possibly stuck switch causing the battery to die.
If power is in the rear, and if you use relays in the rear, you could do it with just two wires and your Sienna switch -- one for each relay coil (and ground to truck). And, those wires would be small gauge, since they'd be handling minimal current. That is sort of what I'll be doing.
If power is in the rear, but you want to avoid relays, then you'd need the larger switch, and 4 wires to run from front to rear, and the wires would need to be a little thicker. This would be the most inefficient method, due to the long run from back to front to back again, for 4 wires. Wouldn't be my first choice.
If, however, you want only two wires, and you use power up front near the switch, and you're willing to use the larger switch, then you could also use just two wires. They'd still need to be a little larger gauge, but not as bad ad option#2.
If you do want to use power in the rear, your solution will be simpler if you install the switch in the rear too. Then, no wires to run, as long as you have a power and ground available. That would be the simplest solution, plus you wouldn't need to worry about finding a switch that matches the rest, since there are no other switches back there.
Fwiw, make sure fuses are used. It's important that fuses are installed such that:
a) as close to power source as possible
b) be smallest necessary to handle load, and def *less* than the power handling of any wiring being used. I plan to use approx 2amp fuse for the motors. Even with, say, 20 gauge wire running from front to back, the wire should be able to handle a short and allow the fuse to blow before burning my gx to the ground. I'll have to doublecheck the charts to verify the value, but regardless, this project will be fused.
Constant power or not, does not really impact the solution. Mine will be connected to ignition power like the rest of the windows -- just personal preference. I want to avoid malfunctions causing windows to accidentally open/close when I'm not in the vehicle, or possibly stuck switch causing the battery to die.
