Head lights
 

My head lights seem really dim, any suggestions?

Please ID car. Are all the lamps dim ? Both low and high beams ? (1) Disconnect and clean plug connectors on back of lamps i.e. electronic spray cleaner. (2) Using long test leads check for poor ground connections. (3) Use meter to check for low input voltage. (4) Test wires for continuity. (5) Check for loose fuse. (6) Check relay if provided. Recommend obtaining a factory manual or other reference that has wiring diagrams specific to your vehicle.

Head Lights
 

2008 CTS, no just low beam, I will do what you suggest.
Thanks

Do you have two dual (low/high) beam lamps plus two high beam lamps ? (wish you had an elec diagram for your car) .... regardless, looking at my "old" '84 Eldo diagrams - can't guarantee the wires and colors are same. Does each of the four lamps have its own ground, usually a black wire connected to the adjacent body. Are they solid and the connection to body firm and clean ? You should have a network of light green high beam wires each attached to the four pull-off connectors at each lamp (you say these high beams all work okay). Next: Each of the two dual beam lamps should have a tan low beam wires attached to each pull-off connector. I would pull and push back-on all of the connectors to be sure they are well connected. Next: Get yourself a hand-held elec meter and using the leads on it see if you are getting 12 volts at each of the two tan low beam connects to the lamps (no current means problem elsewhere). Next: The two tan low beam feeders (on mine) come from a "Dimmer Relay" .... a small metal plug-in cube somewhere under the dash - could be part of the fuse board. Your clue is following the tan wire. Let me know if you can find it.

Head Lights
 

I found 2 empty slots for fuses. One said right low beam, other said left low beam. They were both empty, no fuses. Would it hurt to put fuses in them?

Wow. Who would remove fuses .... unless there was a problem with the low beam circuits (?) It won't hurt anything to put fuses in the slots. Worse case you just waste a one or two fuses. Do it and let me know !

Head Lights
 

I put fuses in the two places that were missing fuses. I can't tell if that
helps untill I drive it at night. I will let you know when I do. Will be a couple of days, got company and all that.

Just need to turn your dash switch on to the head light position. You should see an noticeable improvement even in day light compared to before. One thing tho, prior to putting in the missing fuses I don't know how you got any electricity to light them at all if the fuses were missing (???) but then again I'm not an expert at your system.

A new revelation .... your car must have the day-time running lights safety feature (?) Check your owner's manual. That feature MAY use the low beam lights, or it uses a smaller bulb inside the headlight housing. Because it operates any time the head lights are off, the electrical source for that would come from a different source.

I don't notice any improvement in the lights. There is a number of fuses in the fuse box under the hood that say lo beam and hi beam. I will check that out, maybe today and let you know. Thanks again

I don't know if this helps or not but the book says if you turn the light switch to off, this position turns off all lamps, except the Daytime Running Lamps. My DRL are off.