Headlight Burnout

[jay4runner]

I have a 1990 4Runner. A while back my headlights started burning out way too often. I have had to replace the last few sets of headlights (sealed beams) every few months. One will burn out after a few months and then shortly thereafter the other will burn out. The high beams still work but I can't drive around with them all the time. The one time that I noticed when a bulb burned out it happened just moments after starting the vehicle (don't know if that means anything). Does anyone have any knowledge/suggestions on this problem. Thank you.

 

[aeathb]

Are you using Sylvania Silverstars by any chance?

 

[jay4runner]

I may have had sylvania silverstars in at some point but not just sylvania. I have gone through 3 sets in the last handful of months - sylvania and ge

 

[CJ3Flyr]

I'd check the voltage. On a vehicle that is 'well seasoned' the grounds can deteriorate and "confuse" the voltage regulator. Make sure battery cables are clean and tight. Next make sure all engine block & body ground straps are clean and tight. I'd loosen the ground straps a 1/4 turn and re-snug them.

 

[jay4runner]

Thanks for the tip - i'm going to go and clean/tighten these connections right now.

 

[jeober]

charging voltage (that is engine running) should be apprx. 13.5v in hot ambient, increasing with colder temperatures up to 14.7v max.

 

[Nodd]

The one time that I noticed when a bulb burned out it happened just moments after starting the vehicle (don't know if that means anything).

Starting the vehicle with the lights already on might cause added ware to the bulbs. The voltage sags & spikes quite a bit during starting. Something tells me that's not what you're doing though.

If a bulb is going to blow, it almost always does so when its just been turned on. That's when the filament is under the most stress as it rapidly heats up & expands. So it kinda makes sense it'd blow shortly after starting the truck & turning the lights on.

As others have suggested, I'd check the voltage at the lamp. Another thought is are you buying replacement lights from the same source? Might want to try another store &/or brand.