Customer Support Prog ZHB Halogen bulbs

I am currently waiting for the parts to be ordered and will be getting the new wire harnesses installed within a week or so.

The low beam bulbs in my 2010 Prius typically burn out once per year, always one before the other, and sometimes they have burned out in as little as 2 or 3 months after installing new ones. My car, I believe, is a textbook example of this wiring harness defect.

For comparison, I don't think I ever replaced a bulb in my wife's 2008 Prius, which she had for six years.

I don't think the voltage adjustment will noticeably dim the lights, but simply keep them from burning out due to fluctuating voltages.

After all the evenings spent replacing bulbs in Autozone parking lots before a long commute home from work – and darn are they annoying to access in that compact engine compartment – I am quite happy that Toyota is finally addressing the issue, I just wish it had happened sooner.

 

Yeah, the passenger side one is tricky. I find that if you remove the bolt holding the air intake, you can pull the air intake upright and give yourself an extra few inches of space, which makes it much easier. I eventually started carrying the appropriately sized socket for that bolt in my glove box at all times.

 

Ahhh, but less than a week after getting my letter, my Prius electrical system started acting weird. Then the battery died and I had to get it jumped. I'm wondering if this harness problem could be messing with my alternator.

 

i wouldn't be surprised.

 

Prius does not have a traditional alternator.

The Prius uses a DC to DC converter located under the inverter under the hood.

 

My 2010 passenger side low beam was still original when I received this notice, so it lasted 8.5 years. The driver side has been replaced 3 times, with the last 2 having lasted less than a year. I had the wiring harnesses replaced today, and of course they replaced both bulbs. I did not notice any difference in brightness tonight. The service adviser said they had to perform their diagnostics before they could replace the bulbs and harnesses. After the work was done, I asked what the diagnostics involved and was told there was really nothing, they just replaced it on my report of shortened life of the last 2 bulbs. Hopefully this is the end of this issue.

 

So I've had my dealer do this service and they didn't charge me anything. Before I even had a bulb go out I was thinking of replacing the bulbs with aftermarkets because I think it's really hard to see at night. Has anyone done this since getting the "voltage adjustment wire harnesses"?

 

I have no memory of this recall whatsoever...I don't know if I got that work done on my Prius or not. I remember the battery. Anyway,
In July of 2018, someone had a heart attack in a parking lot and parked his car on top of my Prius. So I bought another one. And just had ZHB recall work done!

 

By my measurements, it shaves about 0.55 volts off at the bulb, ending up a lot closer to an H11's rated voltage of 12.8. Because visible light output roughly follows voltage to the power 3.1 to 3.4 (closer to voltage squared is what you would think at first from Ohm's law, but higher output also shifts more into the visible region, hence the 3.1 to 3.4), this drop might shave 12% off the light output.

But longevity follows voltage to around the power −13 to −16 (!), so the same voltage reduction could roughly double the life of the bulb.

 

I had the dealer warranty enhancement work done Feb 2018 and replacement bulbs continue to be functional. I had a headlight lens restoration done earlier, August 2017, which helped considerably with the quality and brightness of the beam. From where I sit in the car, I'm basically looking right down the headlight beam. So objects in the road are highly visible even on low beam. The halogen bulbs are a slightly yellowish cast anyway, compared to HID or LED. Hard to tell if the brightness has been reduced.