DIY: OEM JDM HID Headlight Conversion - Toyota Yaris Forums

stidnam · 12-14-2018, 04:29 AM

I've looked up the EWD for the P90 Yaris and here's a few points to help you out.

As previously mentioned, the factory halogens are negatively switched. Assuming you had a H4 plug on the stock bulb, then you'll have one positive wire for each side and two negatives to switch between hi/lo. The factory wiring should be coloured as such

- RH positive = Black
- RH Hi ground = Green
- RH Lo ground = Blue

- LH positive = Grey
- LH Hi ground = Brown
- LH Lo ground = Blue

As with all wiring jobs, you should be testing everything with a multimeter as opposed to smashing some wires together and hoping for the best.

I haven't read back through this entire thread to compare everything with the wiring diagram, but here's a basic run down of things you should know

- Because the high and low beam run off the same positive wire, you only have a 10amp fuse for each headlight. This is probably borderline for just running the HIDs - ideally it'd be 15amp, but it's not enough to be running both the HIDs and the Hi beams, which leads me to my next point
- It's very likely that the JDM headlights have been designed to run both the HID and the Hi beam at the same time when you switch on the Hi's. If you look at the reflector bucket you'll notice it has two distinct sections - the upper for the HID lo beam, and the lower part for the hi beam. If these are anything like the 3rd gen JDM lights then running the hi beam without the low beam will produce two elevated spot lights in front of your car, but you'll have no width to the high beams. For this you'll need to wire the lo beams to stay on when you flick to hi beams. You should test the high beams out first, but I highly doubt Toyota designed these to be flicking between hi and lo with the lo being a HID setup. It takes way to long for HIDs to warm up and flicking them on and off shortens their life and the ballasts life.
- Re the above, I'm not even sure if the JDM headlights are positive or negatively switched, or how they've wired up the relays/computer to handle the HIDs.

If I were you I'd be building a new headlight harness with a few relays that are triggered off the factory wiring and wire these things up properly. Even better if you could get the factory wiring diagram ;) - https://page.auctions.yahoo.co.jp/jp/auction/g212047863

If you wanted to do it quick and dirty you could potentially just wire the lo beams in to get the hids working and then sort the hi beams out later.

I've been meaning to write up a piece on how to do all this to a third gen, which is conveniently positively switched with individual fuses per lo/hi beam, which makes things oh so much easier.

If I had my time again, I'd probably just throw bi-xenon morimoto projectors in my lights. While JDM reflector based HIDs are better than the halogens they replace, they have nothing on a good projector setup. Light output and cut off is just not the same :(

Oh and if you're in a country that drives on the right hand side - please don't do this conversion. Think of your fellow motorists. The cut off kicks up to the left. You'll just be blinding oncoming traffic or you'll have the lights set so low they'll be useless.

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12-14-2018, 04:29 AM	#11
stidnam Drives: Starlet Join Date: Nov 2017 Location: Australia Posts: 177	I've looked up the EWD for the P90 Yaris and here's a few points to help you out. As previously mentioned, the factory halogens are negatively switched. Assuming you had a H4 plug on the stock bulb, then you'll have one positive wire for each side and two negatives to switch between hi/lo. The factory wiring should be coloured as such - RH positive = Black - RH Hi ground = Green - RH Lo ground = Blue - LH positive = Grey - LH Hi ground = Brown - LH Lo ground = Blue As with all wiring jobs, you should be testing everything with a multimeter as opposed to smashing some wires together and hoping for the best. I haven't read back through this entire thread to compare everything with the wiring diagram, but here's a basic run down of things you should know - Because the high and low beam run off the same positive wire, you only have a 10amp fuse for each headlight. This is probably borderline for just running the HIDs - ideally it'd be 15amp, but it's not enough to be running both the HIDs and the Hi beams, which leads me to my next point - It's very likely that the JDM headlights have been designed to run both the HID and the Hi beam at the same time when you switch on the Hi's. If you look at the reflector bucket you'll notice it has two distinct sections - the upper for the HID lo beam, and the lower part for the hi beam. If these are anything like the 3rd gen JDM lights then running the hi beam without the low beam will produce two elevated spot lights in front of your car, but you'll have no width to the high beams. For this you'll need to wire the lo beams to stay on when you flick to hi beams. You should test the high beams out first, but I highly doubt Toyota designed these to be flicking between hi and lo with the lo being a HID setup. It takes way to long for HIDs to warm up and flicking them on and off shortens their life and the ballasts life. - Re the above, I'm not even sure if the JDM headlights are positive or negatively switched, or how they've wired up the relays/computer to handle the HIDs. If I were you I'd be building a new headlight harness with a few relays that are triggered off the factory wiring and wire these things up properly. Even better if you could get the factory wiring diagram ;) - https://page.auctions.yahoo.co.jp/jp/auction/g212047863 If you wanted to do it quick and dirty you could potentially just wire the lo beams in to get the hids working and then sort the hi beams out later. I've been meaning to write up a piece on how to do all this to a third gen, which is conveniently positively switched with individual fuses per lo/hi beam, which makes things oh so much easier. If I had my time again, I'd probably just throw bi-xenon morimoto projectors in my lights. While JDM reflector based HIDs are better than the halogens they replace, they have nothing on a good projector setup. Light output and cut off is just not the same :( Oh and if you're in a country that drives on the right hand side - please don't do this conversion. Think of your fellow motorists. The cut off kicks up to the left. You'll just be blinding oncoming traffic or you'll have the lights set so low they'll be useless.