Good morning. Thanks in advance for the response.

I have a 2003 4th gen 4runner. Stock headlight setup.
The issue:
When my headlights are in the on position set to low beam - no issues.
If I snap the light stick forward into the bright position the bright lights do not power on, the fog lights do turn off as expected.
If I pull the stick back into the manual bright position (where you have to hold the stick back), the bright lights will power up and work great.

Some diagnosis:
When the low beams are powered both sockets on either plug show 12v powered on.
When the high beams are powered on one socket turns to ground while the other is at 12v. This is the case on both bright light plugs.
All fuses are in place and good.
Both bulbs are good (and new) (rated at 9 OHMs resistance)
I've attempted multiple good bulbs.

The main question:
What would be causing my bright lights to power on in manual mode on the stick (Pulled back) but not power on when the stick is in the forward position?

My best guess would be the switch gone bad in the high beam on position.

I would get out the multimeter and test the switch in the on position, you may have to remove it to test it if you can't get to the connections

Thanks for the comment. Any direction on where the switch is physically located? I'm not very open to tearing my steering column apart, but if it's accessible i'd like to give your suggestion a try.
Late edit: I have googled and look amog the forum for wiring diagrams of this but cannot seem to find them. any help is appreciated.

Unfortunately it is in the steering column, what all has to be done to remove and or test it I don't know but a Toyota shop manual would have the procedure to remove and replace it.

steering wheel cover is only held on by 3 screws i think.
you might have to take the air bag out, the steering wheel, the spiral cable to to get to the stalks.

I was looking at my steering column and the bottom trim piece behind the steering wheel can be easily removed, turn the steering wheel about 90 degrees and there's 2 screws that you can't see until you turn the wheel, there maybe some more on the bottom of the trim piece but I didn't look, once that bottom trim is off you can see the bottom of the light switch, not sure if it can be removed at that point or not, but at least you can see what else may need to be removed to get it out, or you may be able to test the switch at that point without removing the switch.

now the question is, is he doing this high beam mode with the "key in the on position"?

some functions will need the "key to be in the on position".

was all this done with the key out of the ignition?

Hello all ,

I want to bring this topic up to the top because I too am having the same issues. Regardless of the key in the ignition or engine running position, the headlight high beam should be operational at any time.

I do have one hand however and that is that my dome light fuse keeps blowing. I looked at the EWD diagram but wasn't able to figure out the connection between dome light fuse and high beam. Like the OP, flash to pass works just fine but turning on the high beams independently does not work.

As you can see from the EWD, flash to pass connects the terminal HF from the body ECU. I need to understand what is HF as it is not in the abbreviation list.

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