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One Dim Headlight

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Old Mar 11, 2009 | 12:11 PM
  #11  
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Will do. Just got the car back. Figured out my alternator problem is something with the wiring. SO now I need to figure out where to start.
 
Old Mar 13, 2009 | 11:53 AM
  #12  
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I cleaned of the ground and the problem is still there. Th fuses look fine too. Any other ideas of what would cause this. Passenger side headlight is dim, and the turning signals on the passenger side dont work when the headlights are on. The brights are dim too on that side.
 
Old Mar 13, 2009 | 12:05 PM
  #13  
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Given that both the high and low beams are similarly affected, you should continue to look carefully for whether the shared black ground wire for these lights is damaged anywhere between the bulb receptacle and the ground wire bolt on the engine bay chassis.
 
Old Mar 13, 2009 | 12:28 PM
  #14  
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How does that make the turning signals quit working? They work fine unless the lights are on.
 
Old Mar 13, 2009 | 02:27 PM
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Originally Posted by plethoric33
How does that make the turning signals quit working? They work fine unless the lights are on.
I think it's wise to start by looking for a single cause for two or more problems that seem to be related.

1) Have a look at the headlight circuit diagram below. The only explanation for dimming of both the passenger low and high beams is a fault in the common ground wire that leads to G201 ground connection.

2) Note that the Blk ground wire for the passenger front turn signal funnels into the same G201 ground connection.

My pet theory: The wire harness for the G201 ground wires has been damaged somewhere at one location. At this location, the Blk wire for the turn signal is completely broken, whereas the Blk wire for the headlight is only damaged enough to reduce but not prevent current flow, thereby dimming the headlight. In addition, the broken turn signal ground wire is touching the headlight ground wire, allowing the turn signal to use the headlight wire as ground. Turning the headlights ON (high current) may interfere with the turn signal (lower current) from grounding through the same wire.




 

Last edited by RonJ; Mar 13, 2009 at 02:41 PM.
Old Mar 13, 2009 | 02:39 PM
  #16  
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Thanks for the diagram. Ill give this a check in the morning. And may I ask, where do you get all these diagrams? lol
 
Old Mar 13, 2009 | 02:43 PM
  #17  
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Originally Posted by plethoric33
And may I ask, where do you get all these diagrams?
Click the Civic Manuals link in my signature. lol

By the way, that's my first ever use of lol.
 
Old Mar 14, 2009 | 11:49 AM
  #18  
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I took off the ground screw and washer, sanded down the paint to bare metal, and bam. IT WORKS!!!
 
Old Mar 14, 2009 | 11:56 AM
  #19  
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haha had that problem with my amp ground that's really weird though.......
 
Old Mar 15, 2009 | 08:53 AM
  #20  
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The reason the turn signals were affected was because the electrical current for the headlight couldn't return to ground. Instead, some of it backed up through the turn signal bulb into the turn signal circuit.

Whenever two seemingly unrelated electrical systems start to strangely interact, it is very often a grounding problem.
 



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