So i decided to order some new bulbs (Morimoto 4500k from TRS) as the ones i bought the car with were becoming quite dim and too blue for me. I installed the new bulbs the morning and the passengers fire up perfectly and looks great, but my drivers side does not turn on at all. My first thought was oh great i got a DOA bulb and switch them from side to side and sure enough both bulbs work perfectly in the passenger side. So next i put one of the old bulbs in the drivers and left one of the new ones in the passengers, they both fired up no problem. So i know its not an issue with the new bulbs. My only other idea is that maybe the ballast in the drivers side is dieing out and cannot supply enough power for the new bulb? (i dont exactly know how ballasts work, etc so that may be a silly idea) If it helps, my driver side housing has had a problem with moisture building up inside since i bought the car a year ago. If i should try a new ballast that would be good since id want to take the driver light off anyways and open it up and re-seal it up. If anyone can offer some input that'd be awesome

 

it could be as simple as the fact that you failed to properly seat the socket onto the bulb the first time.
ballasts hardly fail in my experience unless they have been tampered.

your moisture problem would cause the bulb to die prematurely, not the ballast.

 

Did the driver's side work before the bulb? If so did you plug in the bulb correctly(+'s/-'s)? Just checking

 

Thanks for the responses guys. I do not think it was a seating problem as i removed and put in each bulb (both the new ones and both the old ones) in each light multiple times as i was getting frustrated lol. Each set of bulbs do work and fire up. the problem is that the new ones will only fire up in the passenger headlight but not the drivers. The old ones will fire up in both headlights, i put each bulb in each headlight and then reversed it, both old bulbs will work in the drivers side no problem. I replaced each bulb the same way. they have the markings at the base that "align up" to the slots on the projector housing and are snug in there good. The socket slide on no problem and locks into place no problem on each bulb. Aspect, the drivers side worked no problems before this and still will work with old bulbs in it.

 

Just went out and tried fiddling around with em again. Still no luck getting the drivers on. I noticed now though there is no "whine" when i turn the lights on from the drivers light which leads me to think even more its the ballast.

 

 

I dont know what year OPs car is but the 11-13 gang the ballast is outside of the housing (maybe I'm thinking GS where some are inside the housing) but mine outside. As sinister said, the units are not sealed.

That hum you hear from the ballast, makes it sound like its leaking (arcing) internally. I'd say be prepared and grab a new ballast.

What doesn't make sense is that old bulbs still light as they usually take a higher voltage to light off the gas (arc across the electrodes in the bulb) than a new one. So that leads me to think your ballast is indeed the weak link.

My 2013 RS bulb died at 5 year 50,000 miles. It would light, get warm, and then glow orange or shut off altogether about 10 - 15 min later. New bulbs fixed it.
Replaced with Morimoto XB 55000k last July and all is well.
Here is the ballast you need.
PN "81107-53501, COMPUTER SUB-ASSY, H"
Or DDLT003 is the aftermarket replacement. If you buy oem, buy from Yoda as its about $45 cheaper than Lexus for the same part.

If you buy none Yoda parts you'll notice the ballasts state the work with both D2S and D4S which have different voltage specs for the mercury free D4S bulb but aftermarket DDLT003 is half the cost. Its your main lighting so give that some thought.

 

Thanks for the insight guys. My IS is a 2008 with the luxury package (standard HID with AFS). Yesterday i made use of the nice weather and took the light out to give it a good look over. Ive definetly come to think its th ballast. It is majorly corrded and all caked up with white and orange crust...looks pretty nasty. I seem to always have some moisture in my headlight for almost a year now since i bought the car (who knows how long it was liek that before i bought it). Im now looking for a OEM denso ballast, trying to find a new one at a good price, most i see on ebay/amazon are pretty cheap but i think are used off scrap cars (still could be fine) but i prefer a new one. Xenondepot says they sell only new denso ballasts for 120 which isnt too bad. I'll have to heck out Yoda. Its the 85967-52020 D4S that was on the car already. Sinister, thanks for that vid will be really helpful to waterproof the new ballast! definetly dont want this to happen again.

 

 

Yikes - definitely sounds like time for a new ballast. We do, indeed, carry D4S Ballasts and D2S Ballasts; brand new, OEM-grade, from Denso.

~Robert

 

I'm not sure where you got that PN but the where used function of the website that is not our sponsor doesn't show it ever being used in a Lexus. It did pop up on Amazoo tho under the DDLT003 / KDLT003


"81107-53501, COMPUTER SUB-ASSY, H"
I have two new ones. Likely keep them for now! And it seems pretty crazy they didnt seal them/pot them/apply more rigorous application of conformal coating.


This looks like conformal coating that was used in areas to reduce shock. And if you look close you notice the output to the bulb is spot welded into the circuit. Thus, as stated above, the lights connector has to come apart to get the ballast out of the housing. JM2C but the only reason i can think of for not potting from moisture is heat dissipation and cost. Heck, coastal areas rich in salt air would hurt the OEM design over time....

 

 

I definetly do want to pot them, the design lexus made seems pretty silly to put them at the bottom of the headlight. Been waititng for my new ballast to come in and finally it arrived today! Hopefully get some time to take the light out this weekend and pop it in, pretty nervous about opening up the headlight as ive never done that before so i can reseal it and fix the moisture problem. Have read through the DIY's on here for it and seems pretty easy once you get over the anxiety lol. Havent been clear on wether i could put a ballast in the oven though, dont want to ruin the new one! With my TRS ballast order i got some T10 194 LEDs for the parking lights, they were only 11 bucks so i thought hey why not get rid of the ugly yellow stock ones. I went with these ones here: https://www.theretrofitsource.com/t1...ect_restrict=1. They dont match my new 4500k HIDs very well though . Does it look too ricer? Haha.

New Ballast.



New LED Parking lights with new 4500k HID Lows.

 

Check out my YouTube channel with the potting video above. I have a DIY on opening 2IS headlights.

 

The ballast is not inside the housing. No need to worry about it. That said the wires need not be removed for the temperature we're talking about.
Just keep the connectors from touching the rack. Wrap them in aluminum foil.