Toyota headlight issue

Hey guys

I have a friend who owns a 2007 toyota yaris, this car has a problem with the low beams not working, but the high beam works normal. It uses the H4 type bulbs and i believe the head lights are ground side switched..

Fuses are all ok, i cant seem to find the relays for headlights.

Im assuming the ground switch thats in the stalk is faulty but i want to confirm it before replacing.

I have done a few tests..
1. Lights off - all 3 pins have 12v power
2. Low beams on - all 3 pins have 12v power
3. High beams on - 2 pins have 12v power and 1 pin has ground

How do i go about testing this system? I have no experience on ground side switched headlights. I have a wiring diagram for this vehicles headlights, but its not so clear (there arent many "labels" as to what is going on there)

Please help


Sent from my SM-J500F using Tapatalk

You weren't kidding about this that wiring diagram. Love Toyota products, but the diagrams make your head hurt.

I *think* the circuit you're interested in is the one labeled HL at the headlight switch (which they call the headlight dimmer switch assembly). It's a pretty simple system until you add in the DRL garbage. :sick: If it doesn't have DRL's, then the headlight switch grounds the HL circuit directly. If it does have DRL, then the headlight switch grounds the control side of the H-LP/AMT relay, which then switches the HL circuit to ground.

You know that the ground for the headlight switch is good, 'cause the high beams share it. Non-DRL just needs a voltage check at the headlight switch before replacement. DRL gets more complicated. Find the H-LP/AMT relay and go from there.

Ash03 wrote: How do i go about testing this system?

Thanks bud, it's the non drl version..

Do u perhaps have a better diagram for this? The 1 i have doesnt show me the switch pin outs or the actual switch circuit..

I dont understand why toyota wants to have the wiring the opposite of every other car lol

Sent from my SM-J500F using Tapatalk

Tyler wrote: You weren't kidding about this that wiring diagram. Love Toyota products, but the diagrams make your head hurt.

I *think* the circuit you're interested in is the one labeled HL at the headlight switch (which they call the headlight dimmer switch assembly). It's a pretty simple system until you add in the DRL garbage. :sick: If it doesn't have DRL's, then the headlight switch grounds the HL circuit directly. If it does have DRL, then the headlight switch grounds the control side of the H-LP/AMT relay, which then switches the HL circuit to ground.

You know that the ground for the headlight switch is good, 'cause the high beams share it. Non-DRL just needs a voltage check at the headlight switch before replacement. DRL gets more complicated. Find the H-LP/AMT relay and go from there.

You the man Tyler. Thanks for helping me my friend. You're answers are always spot on.

Thank you too pole71, when I am here, which isn't often enough, I always see your name and recognize how much you help out this awesome community. I really appreciate you being here.