Adding a switch to Toyota puddle and floor lights

I would really appreciate it if someone can tell me how to do this, or point me to the thread where this has already been done.

Here are the instructions and wiring diagram on the Toyota lights.

http://toyotaparts.sparkstoyota.com/install/00016-00069-TACOinst.pdf

The lights tie into the dome light circuit and operate like the dome lights. How would I add a CH4x4 single throw switch to the circuit so the puddle lights will come on when the switch is pushed but also work normally otherwise?

I know the dome circuit is negatively switched and I don't want to blow up the ecu doing this. I think I know how but my brain hurts and is going in circles trying to figure this out. Can anyone help.

Thanks

 

The only feasible way of doing what you are asking is: provide a secondary ground through the switch. This will also require a diode so the circuit will not activate the dome light. you will only be able to use two wires on the switch. the input and output. trying to wire it like a normal lighted switch will cause the switch to always be on. this is due to the internal switch design. it should only light up when activated.

 

crude drawing