Headlamp troubleshooting, 2004 Prius

Do you have HID headlights? Assuming you bought the car new and thus no previous owner modified the lights, the HIDs should be a whitish/bluish color and not yellow/orange like halogens.

http://priuschat.com/forums/knowled...andard-optional-equipment-some-countries.html might help. I believe but am not sure that if you have foglights (aka secondary lamps), you have HIDs as well.

If you do have HIDs, it sounds like the bulb or possibly the ballast is on its way out.

 

You need a new HID bulb.

 

First guess would be a bad ground n the electrical ciircuit for that headlight.

 

At 130K miles, I think you're due for a bulb. I think you'd be best off replacing the bulb first.http://www.amazon.com/dp/product/B00480J4KA?tag=priuschatcom-20 should be right and it's a lot cheaper than replacing the ballast/ECU.

Be thankful you have the D2R bulbs.

Toyota switched to D4R (mercury free, apparently) for 06-09 model years. My passenger side (D4R) HID started becoming intermittent after a bit over 5 years, 50K miles and thus wasn't covered by Toyota Prius HID Headlight Class Action Settlement - Consumer Class Action Attorneys - Girard Gibbs LLP (which doesn't apply to you).

 

If you feel the need to test, then you would have to swap the two HID bulbs to see if the problem moves with the bulb or remains on the passenger side.

However since removing and replacing the bulbs is not an easy activity, and one HID bulb is not particularly expensive, IMO you would be better off just replacing the bulb and seeing what happens.

 

If you are somewhat mechanically inclined or have small hands, bulb replacement is not too hard. The only difficult part is removing the black plastic cover. It takes some good hand strength to spin it off.

I highly recommend getting the factory Phillips or Osram (came stock on my '05) bulbs for replacement but there are decent options for $15/pair at places like DDM Tuning or The Retrofit Source.

 

^^
Yeah, the round black plastic cover was VERY hard to remove on mine. That part took me many minutes and my arms were sore the next day.

I agree. Tangent on this: there was a letter that went out to 06-09 HID equipped Prius owners (http://priuschat.com/forums/toyota-...ns-tsbs/74125-hid-replacement-tsb-letter.html) where people who had their headlight ECUs unnecessarily replaced were being reimbursed.

Difficulty of replacing the HID headlights varies depending on the size of your hand, skill and to some degree, luck. I figured I could get the passenger HID done in hour w/o popping off the bumper cover. I was wrong.

I wanted to remove the washer tank to make more room after the spring clip came off but had no luck. I never got the proper answer and had to pop the bumper cover in the end, taking me many hours total.

The links and videos at http://priuschat.com/forums/gen-ii-...d-tank-trying-replace-passenger-side-hid.html should help.

There are some videos, including the one I linked to that involve removing the entire bumper cover. That's too much work.

gives you an idea of how much needs to be pulled to get the assembly out. That's the amount I did. The other videos and pages are helpful so that you know the full process and what's behind there, even if you plan to try to do it w/o removing the cover.

 

Now that I know what needs to come apart, I can remove the entire bumper cover and headlights in 30min or so. It's not fun the first time but I'd be willing to walk someone through the process if needed.

 

I later found out that Carolyn in the video removed a few extra bolts on the side (silver ones IIRC) that didn't need to be removed in order for the headlight assembly to come out.

Look at the 4:50 mark of

for the 3 screws holding in the headlight assembly. I was partly in a hurry, 2 guys were helping out and we were partly doing things based upon the LG video.