It looks like you have a 4Runner. Circuit is very different depending on whether you have DRLs or not. Anytime you want electrical help, please give model and year.

 

I think you're not understanding how a relay works. Once you figure that out, you can very easily accomplish this using the high beam trigger wires to active the switch side of the relay. If you want to interrupt this, install a toggle switch in that switch leg.

 

This is what I did on my 04 Tacoma with DRL's to run Hella Rallye 1000's...

Tap into the wire which supplies power to the high beam filament and run a wire to a switch (or not) inside the cab. You should use a diode here to prevent any back feeding from your new wiring into the existing wiring in series in this run of wire. (the diode should be 'forward biased', anode to the headlight wiring and the cathode to the relay coil or switch) Then run a wire out to a conveniently located relay (the coil) and then ground the relay. Make sure the relay has some sort of BEMF suppression in it or install a resistor (about 100 ohms 1watt) or a reversed biased diode (cathode to positive, the banded end) across the relay coil. This will do exactly what you want if I understand what you want correctly. There are problems if you have DRL's. Since DRL's are on all the time the truck is running power will back feed through the high beam filament and cause the relay to 'chatter' and eventually burn out. You may also notice the auxiliary lights coming on very dimly. If you have installed the switch just switch it off when the head lights proper are not on. This is still a PITA because more or less I wanted it to be automatic, but with a manual off option so...I used a 'Bosch' style relay from PICO products (they have the BEMF suppression built in) and measured the 'pick-up voltage' and 'drop out voltage'. This is the lowest voltage the relay will switch on and off, simply put. I found it to be about 9 volts to pick up and 6 volts to drop out. As the running voltage of the truck is about 14 volts I needed to get rid of about 5 volts This is where electronics 101 comes in... installing a 'zener' diode in the relay control circuit dropped the voltage. If you're still with me try either a 4.7 or 5.1 volt 1watt diode. As DRL run at about 2/3 to 3/4 battery voltage (about 9 volts) puts only 4 or 5 volts to the relay coil which is below the pick-up voltage for the auxiliary relay. This also has the advantage that when the truck is off or battery voltage is low the auxiliary lights will not come on...sometimes! Now I used a lighted switch as well and had the problem that the light would be on dimly and be annoyingly bright at night in use. Again in the ground of the lighted switch I installed a zener diode to drop enough voltage to stop this. I cant recall the voltage but either 5.1 or 6.2 volt seems right to my memory. Depending on what relay and/or lighted switch you use may change the zener diode voltages.

Simple eh!

Don't ask me to post pictures or diagrams...I'm an old curmudgeon and think I'm lucky to be able to work this whole internet crap! Well maybe I could try!

 

Thanks guys. For some reason I was not receiving posts via "subscribe" and did not think anyone responded.