Headlights taking turns going out

toyota
yaris

#1

Toyota Yaris 2008 with 165,000 miles, so far great car. I drive an average of 100 miles a day, and had no problems until the last 6 months that the driver side headlight burnt out. So no big problem, right? just replace it…Well, about 2 months later, the other one went out, replaced it too. This morning at 1:30a.m getting home from work, a hwy patrol stops me because the driver side headlight is out, and gives me a warning ticket.
I took the car to my mechanic so he can check wires or something, but he says that there is nothing to check, that after a while “those” lights go out like that.
I am not sure about that, I really do not want to be changing lights every 2 or so months.
Any suggestions?
Thank you


#2

Bulbs do burn out. It’s a fact of life. And sometimes even newly replaced ones burn out. Bulbs can be defective right out of the box. One other factor that causes newer bulbs to burn out is touching them with bare hands during the install. Skin oil can damage the bulb. Always wear gloves when installing a new bulb, and follow all the instructions that come w/the bulb.

Either the bulbs are burning out or there is a wiring or corrosion problem. When a bulb burns out, it can be verified with a resistance check on both of the filaments. A working filament has a cold resistance of about 0.5 ohms. Do you have the old bulbs still? If so, check and see if they are really burned out. If so, buy another bulb. There may be a warranty on the one that lasted only 6 months, so take it back to the place you bought it with your receipt, maybe they’ll give you a replacement gratis.

If the bulbs ohm test ok, look for corrosion in the connectors or broken or loose wires, esp ground wires.


#3

Did your mechanic check the system voltage with the engine running at around 2k rpm? High voltage will burn out the bulbs, as will touching the glass with your skin.


#4

Thank you for both of your comments. I know for sure the mechanic did not check anything with the engine running. Next time it happens, I am going to buy the bulb myself. My brother did tell me about wiring or corrosion problem. Is this a costly problem? :slight_smile:
On another note, what are your opinions on “transmission flush”? Does the car really need it?
Thank you again.
Gracias!


#5

It does not need a transmission flush and corrosion is not the reason your bulbs are burning out. Corrosion reduces available current and voltage, as does bad grounds. Over voltage from the alternator, skin oils and excessive moisture in the reflector chamber are what damage the bulb. Over voltage should also cause the rest of the bulbs in your car to burn out.


#6

Probably just bad luck–you might have gotten a bum bulb, it happens. If the bulb was changed by someone with dirty fingers or even normal skin oils, that could have caused the burnout. If you change it yourself, use gloves like George said, and/or thoroughly wipe the bulb down with isopropyl alcohol using a lint-free cloth, which will remove oils from the glass. Make sure the alcohol has evaporated before powering it up. Also make sure you use a name brand like Sylvania when getting a new bulb, and not some cheapie.

I would drain and refill your transmission and change the filter. I would not flush it. Also, make sure you use exactly the fluid specified in the manual and not some “universal” transmission fluid when changing it, even if you have to go to the dealer and pay some $$ for it.


#7

My own auto light bulb story. The dome light on my early 90’s Corolla burnt out 3 months after I purchased the car new. The dealer put in a new one under warranty. That one burned out in another 3 months. Dealer put in a new one again. Again, burned out in 3 months. Finally I gave up on the warranty service for the dome light bulb and I went to a retail parts store and bought a bulb there. That bulb has been going strong for 19 years.

I don’t have any experience with transmission “flushes”, but most folks here seem to think the correct way to service a transmission is to drop the pan and replace the filter, then refill with fresh fluid. That’s the way I’ve always done it w/my Ford truck and never had any problems. It’s a fairly simple thing to do, at least on my truck, only a little more complicated than changing the engine oil.


#8

Just to be clear, when I said you don’t need to flush the transmission, I meant that you should only do a drain and refill about every 30k miles. Drop the pan and clean or change the filter every other time, if it has a pan and/or filter. Just don’t flush.

If you have not done any transmission maintenance and the ATF is no longer red, drop the pan, clean the filter, clean the pan and re-install filter and pan, fill the transmission and then hook it up to a fluid exchange machine (not a flush machine) and replace the rest of the fluid. There must be fresh fluid in the pan or you won’t get a 100% exchange.


#9

Thank you for the great advise.