I decided to rig up my Lightforce 170's using the stock harness until I get my dual battery system installed.

I need to tap into the high beam wire, where and which wire is this?

 

What year is your Yota? The FSM is available for free download on the site somewhere just do a search for it. I might could help you if it was an 87ish.
Having said that I would HIGHLY recommend that you not run anything else with your headlights as the stock wiring is barely adequate at best. A simple relay running off an inline fuse from the battery would be a MUCH better idea. You could energize the relay with the headlight feed and get the same effect with out melting you harness and having NO lights.
JMHO

 

I have a 91. The wire is not powering the headlights, it is connected to the relay so when I turn on my high beams the lights come on with them.

 

I tapped into the ignition power wire to the wiper motor so they will not work with the key off but they can be controlled with or without the headlights, I did what worshipmentor said and just used that power to trigger the relay and used a fused wire to the battery for the actual power to the lights.

The way that I found my ignition source voltage was just using my DMM and checking the wires real quick which was faster than looking up the schematic and looking for the wire I wanted.

 

You can use the wiring diagram to find the wire under the dash or use your multimeter to test for voltage at the back of the head light. ARe you going to power the lights off a relay?

 

The harness has a inline fuse coming off the battery and is running off a relay. It just needs input from the high beams to trigger the relay.

 

So if you are really wanting to go off the high beam, and you don't own a DVOM which I am guessing you don't as you could have gotten your answer by now, here you go

 

BTW neib15........
Your headlights in your pic look sick.....literally! If this is what you are dealing with for headlights I dont blame you for wanting something else. I solved this by replacing my stock sealed beams with a pair of Autopal housings and Sylvania Ultra H4 bulbs. I bought both on ebay and spent less than I would have paid for a pair of nasty sealed beams and have TONS of light!
Just my Humble Opinion..........I would recommed that if you do this you look into a secondary harness to drive the headlights too. It is well worth the time/effort/money as the factory headlight harness is barely adequate.

 

When I make my dual battery/alternator swap, I will be upgrading all my light wiring. This is just temporary until I get the funds.

 

I would just run a jumper off of the high beam wire to the relay, so that way when you hit your bright the bigger lights would turn on as well. If you wire it that way you would use youre bright switch to turn on the lights instead of running another switch....I know I did not answer your question but that is what you are talking about doing correct?

 

That is exactly what I am doing. I was just having trouble finding the best location to tap into that high beam wire.

 

just tap into it right at the plug keep it simple ?

 

Elton has the right idea. You could splice into it at that point easily!

 

I put my relays on the fender by the fuse box and from there it's less than 1' to the headlight circuit. Sometimes the easy way is the best way.

 

I second that.