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Headlights don't work except for brights


Cygnus

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So, I got a new W-body five months ago. A 2008 Grand Prix.

 

Now the headlights won't turn on, but the brights will work. I believe the third brake light isn't lighting up either. I just seemed to notice this the other day.

Any ideas to fix this?

 

Also, is it bad form to drive at night using the brights?

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is it bad form to drive at night using the brights?

If there are cars ahead of you (you can see their taillights) or cars coming at you (close enough that you see two individual headlights instead of a single light) you ABSOLUTELY need to use the low beam headlights, shut off the driving lights (if used) and turn off the fog lights unless it's actually foggy out.

 

There is NEVER a reason to use high beams, or driving lights "in town"; and there is NEVER a reason to use fog lights if it isn't foggy or snowing very hard.

 

Way too many morons have forgotten those courtesies, and insist on "photon torpedoing" oncoming traffic, or folks ahead of them on the highway. Either they're too stupid to dim their headlights, or they are under the mistaken impression that the world is all about "them"; and headlights are a way to show "style".

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If there are cars ahead of you (you can see their taillights) or cars coming at you (close enough that you see two individual headlights instead of a single light) you ABSOLUTELY need to use the low beam headlights, shut off the driving lights (if used) and turn off the fog lights unless it's actually foggy out.

 

There is NEVER a reason to use high beams, or driving lights "in town"; and there is NEVER a reason to use fog lights if it isn't foggy or snowing very hard.

 

Way too many morons have forgotten those courtesies, and insist on "photon torpedoing" oncoming traffic, or folks ahead of them on the highway. Either they're too stupid to dim their headlights, or they are under the mistaken impression that the world is all about "them"; and headlights are a way to show "style".

 

I agree with this EXCEPT for the fact that 85% of cars don't have real fog lights although they are called as such. Most "fog lights" on modern cars are nothing more than decorative lights that usually do nothing more than light up the immediate foreground around the bumper. These lights usually don't blind anybody and I'm willing to infer that manufacturers have purposely done this due to people misusing the fog lights as decorative lights. This is probably why most manufacturers are probably switching over to LED strips where the fog lights would normally be. In any case, I personally feel if the fog lights are aimed so the lights light up only a foot to a foot and a half in front of the car (basically you can't drive with them on or the lights are overpowered by the low beam headlights) then I see no real harm about it.

 

The real issue here is HID lights and people that slap HID lights in their car and don't take the time to adjust them properly so they don't blind the whole roadway. In reality, the lights shouldn't be used unless there is a projector retrofitted to the headlight housing but if people must insist, the least they can do is aim them properly so when you have a HID equipped car in your rear view mirror, the scattered light isn't blinding.

 

Now as far as the O.P.'s issues, he needs to check his headlight bulbs first to see if they're even good. After that, it would be a good idea to check voltage in the connecting clip with a multimeter. If there is no voltage, then the next step is to check the headlight relays, fuses, and wiring.

 

As far as the 3rd brake light goes, that is a LED strip so once again, check the wiring with a multimeter and go from there.

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So, I got a new W-body five months ago. A 2008 Grand Prix.

 

Now the headlights won't turn on, but the brights will work. I believe the third brake light isn't lighting up either. I just seemed to notice this the other day.

Any ideas to fix this?

 

Also, is it bad form to drive at night using the brights?

Its either a bad headlight relay or a bad multifunction switch.

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Some body control modules switch the headlights on, that's something we see on a car new enough to have daytime running lights, like 2008 probably does. Just guessing, not sure. Incidentally, have you checked for voltage at the headlight plugs? It's not all that crazy to think you may have 2 bad bulbs.

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Some body control modules switch the headlights on, that's something we see on a car new enough to have daytime running lights, like 2008 probably does. Just guessing, not sure. Incidentally, have you checked for voltage at the headlight plugs? It's not all that crazy to think you may have 2 bad bulbs.

2008 would probably have automatic headlights... How it's implemented is something different but yeah I would doubt the daylight sensor would cause the low beam to not work. I'm betting on it being electrical. That's why I suggested testing with a multimeter.

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2008 would probably have automatic headlights... How it's implemented is something different but yeah I would doubt the daylight sensor would cause the low beam to not work. I'm betting on it being electrical. That's why I suggested testing with a multimeter.

 

I didn't see that there, you beat me to the obvious. Another helpful tool may be alldatadiy.com, pretty good online repair manual that has fairly accurate schematics.

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