2010 Prius headlights stopped working.

By any chance, do you keep your headlight switch set to the On position all the time?

SCH-I535

 

Aha, thought so. I suspect that your bulbs are being damaged by the current fluctuations during startup.

Most cars have surges present when everything is going on during startup (starter motor cranking, etc). I didn't think this was a problem in the Prius because it doesn't have a high amp draw starter, but I had a relay fail prematurely in my highbeam DRL mod module I have. The relay draws power immediately when the car is in Ready mode. The failed relay terminals displayed residue from arcing.

I ended up putting in a delay relay to prevent damage to the relay. The delay ensures that power to the circuit (relay) is stable, because it doesn't come on during the initial period of time when all the electronics are being initialized and current/voltage fluctuations are present.

I suggest you either install a delay relay as well in the headlight circuit, or turn the lights on manually after the startup period takes place. A few seconds is all that's needed.

Also, never touch the bulbs with your fingers. The oils from your hands will create a hot spot on the bulb leading to premature failure of the bulb.

SCH-I535

 

Which lights on top? The parking lights?

They were probably getting old and the filaments were getting thin. The current fluctuations burned them out.

SCH-I535

 

Did you only recently start leaving your switch in the On position?

SCH-I535

 

Yeah, changed them more than a few times between LEDs, incandescent, different colors, lol.

Just reach up behind the headlight and turn the bulb holder a quarter turn and remove carefully. Put the new bulbs in, without touching them, make sure they are well seated in the sockets so they don't fall out in your headlight housing, then carefully put the bulbs through the back of the headlight housing and give it a quarter turn to lock in place.

The passenger side is harder to get to. You have to remove some 10mm bolts holding the coolant reservoir hose and move them aside so you can reach the bulb.

SCH-I535

 

Please elaborate, what is the problem, and what was done to fix it?

Galaxy Nexus ? 2

 

Hopefully it's not the multifunction switch or the headlight relay. The switch and stalk is expensive, so with diagnosis and labor it will be $$$.

Galaxy Nexus ? 2

 

I realize this is a posting from many years ago but I was hoping someone would maybe be able to help me with my 2010 Prius.
All of a sudden last night while driving home I realized I couldn’t see infront of my car while driving because the lights were so dim. So once I looked at my lights it looks like only the parking lights are working on both sides of my headlights.
Can someone please advise me as to what to do?
Now that I’m typing this I am thinking about the fact that my lights seemed really dim always. Was this a sign that the lights were burning out slowing and do they go out the same time like that usually?
Thank you in advance for any help you can give me with my 2010 Prius.