Australian 2013 headlights *NOT* negative switched??

[arose62]

I'm adding an LED light bar to my 2013 Yaris L 2-door hatchback, and after seeing all the discussions about negative switching, I spent time doing searching, collecting wiring diagrams, noting that Narva had a negative switched wiring diagram including a diode, etc.

However, when I went to check the voltages present on the headlight connector pins for lights off / low beam / high beam I was getting more and more puzzled.

I made a simple straight-through connector-to-socket "harness" with exposed spots on each wire so I could test voltages with the bulb in circuit and operating, and found that on my Yaris, the left headlight (only one I've tested) really, really looks like it's positive switched.

The top terminal is 12v and the left (looking at base of bulb) terminal is 0 when low beam is on.
The right terminal is 12v and the left 0 when high beam is on.

So, either my Yaris is just positive switched, or, there's something really confusing going on.

Any reason I shouldn't proceed on the assumption that it's straightforward positive switching?

[kevinj93]

Hi Arose,

Yes, according to the wiring diagram, The headlights are positive switched. I think the earlier Yaris models were negative switched.

I have attached the Headlight block diagram and wiring diagram for you.

I think the "Dim" relay is drawn incorrectly in the wiring diagram, but the pin connections from it should be correct.

[arose62]

Thank you!

I can now finish this, with a simpler wiring plan than the one I had been developing.