2010 Legacy low beams unsafe

[snakedoc]

I bought a 2010 Legacy a year ago and have found that it is virtually unsafe to drive at night because the low beams are so dim.  I resurfaced the lenses in hopes that it would solve the problem, but no dice.

 

I am no whiz with cars but am willing to try some things on my own before forking over $$.

 

So far I've seen suggestions of:

--Fuses

--Ground wire

--DRL assembly

 

I don't even know where the ground wire is...any advice to get me started?

 

Thanks all.

[Bushwick]

First thing's first. 4 year bulbs with heavy on-time usage won't be as bright as new. If the suspension has been altered or the rear sits TOO low, it'll force the light pattern high or conversely too low if the rear is too high. If the previous owner tinkered with the headlight pattern (there are adjustment screws on each head light) that can cause issues as well with where the beams are focused.

 

 

Try this:  Wait until night. Park on a completely level section of concrete (flat driveway 20' away from garage door works). If nothing is available at your home, try a business with a big wall and flat parking lot. Adjust the headlights and use their centered beam on the wall as reference to where you want to see. Try and keep them on the pavement (barely) while not blinding oncoming traffic with too high or too far left. I personally like to center my bulbs so they are even height, skimming the road surface (no point having the beam dead center on the road as you won't see out ahead of you). I usually fan them out (left and right) a bit so there isn't a ton of cross-light which is a waste. Go drive down a dark road with heavy tree lines. The bulbs, if set correctly, will catch everything in front of you, and a decent amount of everything to each side (so children on sidewalks or deer grazing should be seen).

 

 

If they are still too dim, let the engine run with headlights on (and anything else typically on) and check the voltage at the battery. If your alternator is dying, it might be too low to supply the headlights correctly. Should be around 13v running.

 

 

If after all that, there are still too dim, consider replacing both bulbs. I REALLY like the Silverstar bulbs. They are *much* brighter than stock, but don't burn out as quickly as the Goldstar versions. The Silverstar are a few dollars more than the cheapest bulbs, but the amount of light they shed will be worth it.  

 

For comparison's sake, my 95' with properly adjusted Silverstars and low beams on, can light up a good 2+ blocks ahead on a completely dark road. I can also see a good 40' on each side. Love them. Have them in my other car and similar performance. High-beams on and I'm a good 4-6 blocks ahead.

Edited November 17, 2014 by Bushwick

[1 Lucky Texan]

if the car uses 9005 for that location, you can 'hack' 9011 bulbs to fit - much brighter.

 

EDIT - low beams seem to be H7, not aware of any 'hack' for those.

 

 

high beams are upgrade-able to modded 9011 though.

Edited November 17, 2014 by 1 Lucky Texan

[snakedoc]

Thanks.  I replaced one of the bulbs awhile back with a Silverstar but it did nothing for the brightness.  They are so bad that we don't drive that car at night.  I will try re-aligning the lights and go from there.

[Bushwick]

Thanks.  I replaced one of the bulbs awhile back with a Silverstar but it did nothing for the brightness.  They are so bad that we don't drive that car at night.  I will try re-aligning the lights and go from there.

 It's definitely NOT that light. Either they are way off and angled up into nowhere, or your alternator voltage is below 12v. Play around with the adjustments. 

 

 

EDIT: It might be worth taking a voltmeter and also checking voltage AT the actual light. Unplug connector, turn headlight switch ON, then probe the connector for power. Below 12v will cause the lights to be too dim. 

Edited November 17, 2014 by Bushwick

[mikaleda]

I bought a 2010 Legacy a year ago and have found that it is virtually unsafe to drive at night because the low beams are so dim. I resurfaced the lenses in hopes that it would solve the problem, but no dice.

 

I am no whiz with cars but am willing to try some things on my own before forking over $$.

 

So far I've seen suggestions of:

--Fuses

--Ground wire

--DRL assembly

 

I don't even know where the ground wire is...any advice to get me started?

 

Thanks all.

What kit did you use to resurface the lights? Some headlight resurfacing kits don't work well. If the kit didn't have you sand the lens down then that is probably what the problem is.

 

Now assuming the headlights are resurfaced properly. the next things to check are headlight adjustment, bulbs, then wiring or power source

 

More than likely your problem is going to be adjustment or new bulbs

[snakedoc]

I don't recall the brand, but one of the well reviewed ones.  Yes it had me sand it for several steps.  Definitely looks clearer but not getting a lot of result from it.

 

Does anyone know if Advance Auto can do the voltage checks for me?

[brus brother]

http://static-forums.fatwallet.com/static/attachments/439521_scan_pic0001.jpg

The above link has coupons to a variety of somewhat useful stuff from Harbor Freight Tools. Coupons are valid until 2/15

The coupons are for FREE items and some require no purchase. Walk right in take coupon or scan from smart phone to cashier and you're on your way.

There is a multimeter in the mix that you should have in your kit and learn its applications. Free with no purchase required.

It's good enough for what you are looking for here.

I wouldn't trust their torque wrench if you were doing HG's but a free wire brush or pick set or a tarp, count me in.

 

Edited November 18, 2014 by brus brother

[Fairtax4me]

My biggest question is, are the low beams actually turning on? If only the Daytime Running Lights are on the lights will appear very dim at night. Identify which bulbs are the low beam bulbs, turn the switch on and make sure those bulbs light up.

 

Have you checked all of the fuses? That's step 1 before even replacing any bulbs.

 

If you had a charging system problem, there would be other issues. Dim headlamps is the last sign of low battery voltage. You'll get warning lights for the ABS, Airbag, TCS/VDC, and you'll probably get a CEL before you notice the headlamps dimming due to low voltage.

[Bushwick]

@ Fairtax,  If you place a large enough demand on an alternator or it's getting weak, it can dip to 11-12 volts w/o throwing codes (overly demanding amplifiers can do this; as can bad wiring feeding the headlights or melted connectors, shorts, etc. lower the voltage at the head light). At that voltage, his lights will be dimmer than they'd be at 14v. It's smart to see what the charging system is doing and what voltage he's seeing at the actual bulb to rule out. Can't always expect the CEL will pop on. It's also possible for an alternator to not kick on the charging circuit at idle(alternator rebuild with incorrect pulley size, too slow of a speed to kick on).

 

 

How many times have come across a car with a dead battery that you jumped, got started, but the alt. wasn't charging the battery? Did you see a CEL beforehand? I've seen this happen a lot w/o any dash warnings in plenty of cars with OBDII.

 

 

Example: I had a 130 amp alt. rewound to 290 amp in my old Mark VIII as I had 120 amp draw from sub amp alone. The alt. shop never told me the alt. would be running too slow at idle to charge. So every stop light the the alt would quit charging. Voltage would drop to 12-11v. It never threw the CEL for the low voltage though. I went and had a custom one-off pulley ground from a company in Texas. They increased the the idle speed of the alternator by about 250 rpms, so it'd spin fast enough at engine idle to charge. If his alt only kicks on at 550, and the engine idled at 500, he won't get a CEL and the alt won't charge at that speed. 

 

Point is, don't discount  and cover all the bases.

Edited November 18, 2014 by Bushwick

[heartless]

Example: I had a 130 amp alt. rewound to 290 amp in my old Mark VIII as I had 120 amp draw from sub amp alone. The alt. shop never told me the alt. would be running too slow at idle to charge. So every stop light the the alt would quit charging. Voltage would drop to 12-11v. It never threw the CEL for the low voltage though. I went and had a custom one-off pulley ground from a company in Texas. They increased the the idle speed of the alternator by about 250 rpms, so it'd spin fast enough at engine idle to charge. If his alt only kicks on at 550, and the engine idled at 500, he won't get a CEL and the alt won't charge at that speed. 

 

A subaru is a bit of a different beast than your Mark VIII is - this much I do know.

 

Had a Mark V for several years, pretty familiar with those - granted the VIII is a more complicated beast than the V was...

Also on my 3rd personal Subaru - we have had 7 registered ones - from 1988 thru 2006 - and a crap load of parts cars go thru here...

 

Every Subaru we have had that has had charging system issues has caused multiple dash lights to come on looong before the the voltage dropped enough to dim the headlights. I sincerely doubt that the charging system is the issue here.

 

poor voltage at the headlight connector, on the other hand, is completely plausible, as are some of the other suggestions - misalignment, bad ground, bad fuse, old bulbs - or a combination of those.

 

To the OP, if you have a Harbor Freight tools near you, go pick up one of thier cheap digital meters - this one should do just fine - to test voltage at the headlight connector.

 

Advance Auto can do a free charging system check for you - put your mind at ease on that front if you like - but to check voltage at specific connectors - probably not...

[Bushwick]

Yeah, I only used the Lincoln as it was an OBDII car at the alt was modded. At idle, it wasn't spinning fast to kick on. The OBDII stuff wasn't detecting an issue and the car ran, but at idle it was only running off battery until the engine speed went up. Any time you buy a used vehicle, you have no idea what the PO did to it. At idle, the headlights were so dim it wasn't safe either   If his dummy charge light was unhooked, he wouldn't know if the voltage was too low either.

Edited November 19, 2014 by Bushwick

[Bushwick]

Actually, on a hunch I went ahead and waited until the Legacy was at full operating temp and had a full charge on the battery by the time it made it to the local gas station 15 minutes ago. While leaving the engine running but turning all the accessories off, I popped the hood and pulled the "on" wire (the 3 wired plug on top of unit, NOT the actual charging wiring that runs to battery) and let it set for a minute. It had absolutely NO lights pop on in the dash despite the fact it wasn't charging. That's because the battery was still at a "safe" voltage and hadn't dropped enough to trigger any dash warnings. So, the result with the Mark VIII is the same as with the Legacy. As long as the battery has an acceptable voltage, you can unhook your top alt. plug and no CEL, etc. should come up if it's like mine.

 

 

He put a Silverstar bulb in and is saying that was dim too. If someone before him stuck an incorrect alternator from a base model that makes too little amperage to handle all the car's electronics, while running all his stuff it might be OK for small current demands, turning a bunch of accessories ON might be taxing the alt beyond what it's capable of, especially if it's NOT working as it should. Hence we should know what his alt. voltage is AND his voltage at the lights to see if a drop in voltage is occurring at the alt, after the alt, or at the lights, etc. 

[heartless]

which is why I suggested..

 

A ) get the charging system checked out, which Advance Auto, and others, will do for free. (I specify Advance because the OP asked about them checking voltages)

 

B ) he pick up a cheap multimeter to check some voltages at specific locations, like at fuses and the headlight connectors, which Advance will not do.

 

Edited November 19, 2014 by heartless

[snakedoc]

Wow.  Awesome discussion...wish I knew what the heck it meant

 

I just adjusted the vertical height of the headlights (maybe too far...).  At 25 feet they were barely hitting the garage.  I brought them up to aout 3 feet.  Only driven around town but haven't noticed a real difference--need to get out on some really dark roads. 

 

I still feel like there is another issue going on.  I think my next stop is to Advance and have them check the battery, etc.  I'll report back with those findings.

[Fairtax4me]

 

It had absolutely NO lights pop on in the dash despite the fact it wasn't charging. That's because the battery was still at a "safe" voltage and hadn't dropped enough to trigger any dash warnings. So, the result with the Mark VIII is the same as with the Legacy. As long as the battery has an acceptable voltage, you can unhook your top alt. plug and no CEL, etc. should come up if it's like mine.

As an immediate/temorary loss you'll likely not notice anything wrong. No lights on the dash, and I'll bet your headlamps were not substantially dimmer either. 

 

If its a continued problem, such as over the course of several days or weeks, you'll likely first notice it when starting, because even a partially charging alternator can still keep up with the current demand for the headlamps. But over time the charge level of the battery will decrease, and slow starting will be the first major sign. When the battery voltage finally drops below about 11v, that's when the warning lights will start to come on, but you will be hard pressed to notice a major difference in the headlamp output. 

 

 

I just adjusted the vertical height of the headlights (maybe too far...).  At 25 feet they were barely hitting the garage.  I brought them up to aout 3 feet.  Only driven around town but haven't noticed a real difference--need to get out on some really dark roads. 

You may have adjusted them too far. The beam pattern for the low beam lamps is designed to illuminate the roadway directly ahead of you, about 75-100 feet out. Beyond that the light is not focused well enough. You lights may now be too high, which decreases your immediate visibility, but also points the lights into other drivers eyes. 

 

 

Another issue that I've seen with newer vehicles is the way the bulbs sit in the headlamp housing. In order to get the maximum output the bulb has to be aligned perfectly with the reflector. Many low beam bulbs now have a notch or alignment pin that has to be lined up with a similar recess or pin in the housing, or the bulbs will not sit perfectly in the housing. This moves the center of the lamp out of proper alignment with the reflector and will cause the light output from the housing to be distorted. This affects the output of the beam, and can cause it to be either too high, too low, or it can spread the beam too wide, or direct it into too narrow of a pattern. 

Think of an old mag-light where you can adjust the beam pattern of the flashlight by turning the end, this moves the bulb into a different position relative to the reflector, and changes the light output to either a very wide pattern, or you can adjust it to be very focused in one spot. This changes how much you can see with the light, and you can either see a wide area up close, or focus the pattern to see further away. The same principle applies to the headlamps in your car, if the bulbs are not inserted properly the light will not be focused the way it was intended to be. 

[Silent Bob]

Another issue that I've seen with newer vehicles is the way the bulbs sit in the headlamp housing. In order to get the maximum output the bulb has to be aligned perfectly with the reflector. Many low beam bulbs now have a notch or alignment pin that has to be lined up with a similar recess or pin in the housing, or the bulbs will not sit perfectly in the housing. This moves the center of the lamp out of proper alignment with the reflector and will cause the light output from the housing to be distorted. This affects the output of the beam, and can cause it to be either too high, too low, or it can spread the beam too wide, or direct it into too narrow of a pattern. 

Think of an old mag-light where you can adjust the beam pattern of the flashlight by turning the end, this moves the bulb into a different position relative to the reflector, and changes the light output to either a very wide pattern, or you can adjust it to be very focused in one spot. This changes how much you can see with the light, and you can either see a wide area up close, or focus the pattern to see further away. The same principle applies to the headlamps in your car, if the bulbs are not inserted properly the light will not be focused the way it was intended to be. 

This.

 

The low beam bulbs on a '10 are a pain to change with the lamps in place.  Very easy to misalign the bulb and have it be very dim and aimed way off.  Make sure they are correctly seated in the housing.  I have seen this happen many times.

[mikaleda]

Plus 1 on bulb mmisalignlent they are a pain to get to, especially if it has the six cylinder in it.