211 Posted January 20, 2008 Share Posted January 20, 2008 About two months ago the passenger side headlamp bulb went out. Bought a two pack of bulbs from the local auto store and replaced not one, but BOTH of the bulbs. The working one I kept in the glovebox as a spare (wrapped in paper towel and kept in a film canister so it didnt get broken). Now the other day, my drivers' side bulb goes out for no reason. Figured okay, I'll put in the old spare for now till I have time to buy another pack. Well the VERY next day the passenger side bulb goes!!! WTF!?!I'm hoping this is just a fluke deal and not a weird electrical problem... Link to comment Share on other sites More sharing options...
The Dude Posted January 20, 2008 Share Posted January 20, 2008 My first suspect would be the replacement bulbs. Believe it or not, manufacturers make bad lots of bulbs from time to time. So, try a different brand of bulb. You can also check the voltage present at the bulb terminals if you want to be sure that voltage is still in spec. Over voltage can kill a bulb in short order. Link to comment Share on other sites More sharing options...
r_kirky Posted January 20, 2008 Share Posted January 20, 2008 I had this problem once on a 96 legacy. After replacing them a few times I noticed that the plug was cracked and starting to melt. Replaced both plugs with generic napa ones and had no further problems. Link to comment Share on other sites More sharing options...
Gloyale Posted January 21, 2008 Share Posted January 21, 2008 Are you using "ultra-brite" or anycrap like that? I've had problems with the extra bright bulbs burning out the connectors. Replace the connector and use regular bulbs. Or do a proper HID conversion. Link to comment Share on other sites More sharing options...
brus brother Posted January 21, 2008 Share Posted January 21, 2008 Not sure of your model year but our 2005 OB blew both headlamps in quick succession and were replaced under warranty apparently being an issue with factory installed bulbs from a bad lot. Link to comment Share on other sites More sharing options...
jp98 Posted January 21, 2008 Share Posted January 21, 2008 I know that with quite a lot of the newer bulbs that if you handle them and get any and I mean any grease on them even from your fingers they will burn out quite quick. Another problem is bad grounds going to the lights. Jim Link to comment Share on other sites More sharing options...
edrach Posted January 21, 2008 Share Posted January 21, 2008 I had the same problem on our old '86 GL wagon. Turns out the voltage regulator on the alternator was toast and outputting 17+ volts to the headlights! Have the alternator checked quickly, since if it's the alternator there are much more expensive parts to fry other than the headlamp bulbs. Good luck with it and I hope it was just a bad batch of bulbs. Link to comment Share on other sites More sharing options...
211 Posted January 21, 2008 Author Share Posted January 21, 2008 I had the same problem on our old '86 GL wagon. Turns out the voltage regulator on the alternator was toast and outputting 17+ volts to the headlights! Have the alternator checked quickly, since if it's the alternator there are much more expensive parts to fry other than the headlamp bulbs. Good luck with it and I hope it was just a bad batch of bulbs. I really hope it's not the alternator because it was JUST replaced, I mean like 3 weeks ago. It was a chicken/egg thing. Both battery and alternator died, which witch killed which, I don't know but the point is the alternator and battery are new. That being said, one thing I do notice now that I have a new alt/battery is whenever I'm at a stop and the car is idling and I apply the brake lights the headlamps dim just a little bit. This may not be related to the "eating of headlamps" but I never noticed that before the new alt/batter went in (yes, contacts are clean and tight). Besides that, I am very careful not to handle the new bulbs with bare hands. Link to comment Share on other sites More sharing options...
edrach Posted January 21, 2008 Share Posted January 21, 2008 I really hope it's not the alternator because it was JUST replaced, I mean like 3 weeks ago. It was a chicken/egg thing. Both battery and alternator died, which witch killed which, I don't know but the point is the alternator and battery are new. That being said, one thing I do notice now that I have a new alt/battery is whenever I'm at a stop and the car is idling and I apply the brake lights the headlamps dim just a little bit. This may not be related to the "eating of headlamps" but I never noticed that before the new alt/batter went in (yes, contacts are clean and tight). Besides that, I am very careful not to handle the new bulbs with bare hands.Do you have a digital voltmeter? It's pretty easy to check out the alternator voltage. The lights shouldn't dim when you apply the brakes. There's definitely an issue here you need to follow up on. Did your dealer do the alternator and battery? If so, go back and have them check it out. Even if they say it's okay, go to any autoparts store and get a second opinion. Link to comment Share on other sites More sharing options...
211 Posted January 21, 2008 Author Share Posted January 21, 2008 Do you have a digital voltmeter? It's pretty easy to check out the alternator voltage. The lights shouldn't dim when you apply the brakes. There's definitely an issue here you need to follow up on. Did your dealer do the alternator and battery? If so, go back and have them check it out. Even if they say it's okay, go to any autoparts store and get a second opinion. Did the work myself. Bought the alt/battery at the local Schucks autoparts store (Schucks, aka. Checker, Kragen, CSK). It was this local autoparts store where I had the original battery tested, they said it was bad, changed the battery and they tested the alternator, the alternator was bad. After I changed the alternator I went back to return the core and had them test it again, they said everything was okay. I've heard mixed opinions about testing the alternator w/ a DVM. I've heard the DVM is not very reliable- like if the alternator is passing too much AC ripple, it won't be very evident on the DVM. Either way, this is not normal huh? We have an auto electrical specialty shop in town, I'll have them run a test and see what they say (if I remember correctly, they use the same tester Schucks uses... Link to comment Share on other sites More sharing options...
edrach Posted January 21, 2008 Share Posted January 21, 2008 Did the work myself. Bought the alt/battery at the local Schucks autoparts store (Schucks, aka. Checker, Kragen, CSK). It was this local autoparts store where I had the original battery tested, they said it was bad, changed the battery and they tested the alternator, the alternator was bad. After I changed the alternator I went back to return the core and had them test it again, they said everything was okay. I've heard mixed opinions about testing the alternator w/ a DVM. I've heard the DVM is not very reliable- like if the alternator is passing too much AC ripple, it won't be very evident on the DVM. Either way, this is not normal huh? We have an auto electrical specialty shop in town, I'll have them run a test and see what they say (if I remember correctly, they use the same tester Schucks uses...DVM will measure ripple also although that's a moot point since the battery acts as a large capacitor to smooth out the ripple. Important thing is to determine the DC voltage at the battery at idle (around 12VDC) and then increase the rpm to about 2500; voltage should increase to around 14 to 14.5VDC maximum. If the voltage increases above 15VDC the voltage regulator in the alternator is shot. And that would be a good reason for your headlight bulbs to burn out. Measure the voltage at the battery terminals. If you want to measure the AC voltage (ripple) then set the DVM to AC and measure it also. I'd have to check my car to see what's normal for ripple. Generally there are three important things to know about alternators: 1) DC voltage output: Is it enough to charge the battery and run your accessories. And is it limited by the regulator to 14.5 VDC so it won't damage your electrics. 2) High ripple indicates that one of the output diodes is open; but this would show up as low output (i.e. less than 12 VDC at idle). 3) Are the bearings still good; if the alternator "growls" when the engine is running it's probably time to have it replaced or rebuilt. Given the symptoms, I would bet you a beer that the Schuck's alternator's regulator has failed in yours. Link to comment Share on other sites More sharing options...
edrach Posted January 21, 2008 Share Posted January 21, 2008 If you haven't already read it, look at this thread: http://www.ultimatesubaru.org/forum/showthread.php?t=84248 I haven't a whole lot of faith in the after-market rebuilds. Also, there was a thread recently where the poster went through two rebuilds only to find that both times the after market place had given him the wrong model (the most expensive one to boot!). Going with an OEM for his car fixed all his problems. I think you're right to have the electrical shop in town test what you've got. If you're ever down in Seattle I can give you the name of the shop in Ballard that I trust to rebuild all my alternators.....real "old school" guy who really knows his stuff. Link to comment Share on other sites More sharing options...
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