Headlight bulbs burning out every month or two(Low Beam/DRL)

Check the voltage of the electrical system by connecting a voltmeter across the battery terminals while the engine is running at operating temperature (warmed up). It should read in the 13.5-14.5V range. If it is significantly higher, say 15V or above, your voltage regulator is not working properly. Excess voltage will cause bulbs to burn out more frequently. The regulator is an integral part of the alternator so if this is your problem the alternator will need to be replaced.

If you are handling and touching the glass part of the bulbs during installation with your bare fingers, then that may be the source of your trouble. Skin oil deposits from your fingers will cause hot spots to form on the bulb glass. The over heating will cause the bulbs to burn out quickly. Suggest in the future to use rubbing alcohol on a kleenex to clean the glass part of the bulb prior to installation. Once cleaned, do not touch the glass part with your hand or fingers. I hope this solves your problem. Bulb manufacturers should advise the buyer of this potential problem, but no, I guess they want to sell more bulbs.

Yes, REAl quickly...like within a second of power application.

This cause does not take days or weeks to do it's work.

Depends on how oily are your hands. Some folks reek oil. Even if you been washing parts in gasoline with your bare hands, there is still some oil but there would be a lot less which means the hot spot wouldn't get as overheated as the sausage pizza-eating, non-washing, slimy mechanic handling your bulbs.

If you handle the bulb with a bare hand there will always be some grease residue. Try to handle with a cloth. If you do get your fingers on bulb, you can use alcohol to take off grease.

I think we're getting off onto a pointless tangent about this oily fingerprint on glass business. I've changed the bulbs on my 2000 OBW before, and it's damn near impossible to touch the glass while you're installing. The bulbs usually have a flange between the glass part and the metal part. In order to install the bulb you need to hold onto the metal part.

It's possible that maybe the headlight fuse is badly calibrated, or even the wrong type altogether. Perhaps if its a rated 20 amp fuse, it might actually be letting through 22 amps instead?

Yousuf Khan

Not possible. A fuse does not "let through" a certain amount of current. The bulb itself determines the current, and the fuse simply blows if it seems more current than its rating. The only thing that can cause a fuse to mis-operate is a partial melt in a previous event. All that will do is melt the fuse prematurely next time. If this was the case, the OP would have had to replace the fuse to get another bulb to work.

First thing I would check is the voltage. And check to see how the voltage changes when the RPMs go up to ensure the alternator is not screwing up.

Chico

You could see if you have moisture inside the headlamp. Had that happen on a honda.

Aside from the finger-on-glass issue which is real important, check on the charging voltage which should be 14-14.4 volts at a fast idle. Too high a voltage is death on bulbs. Ed

FWIW, Subaru just told my wife that they've had a run of bad headlight bulbs from their supplier, explaining why she had hers start burning out after a year.

- Rich

-- Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.

Really? I've yet to see a bulb (packaged for US sale) that doesn't come with a warning that the glass should be kept clean and possibly cleaned off with rubbing alcohol if in doubt. They also warn that the halogen bulbs are pressurized and could burst if handled improperly.