2004 LS Headlights dim

[dorlow]

Ok, I'm not sure if this is related to the problem I posted here...

http://www.automotiveforums.com/vbul...12#post6826912

Maybe it's all in my head. My lights seem awfully dim while driving at night lately. I can barely see the road while I have them on dim. I used to be able to see fine. I'm also 99% sure my odometer and radio is about half the brightness it was when the car was new (like I posted in the post above.)

I was thinking today that maybe my battery or alternator is bad. I have a Black & Decker battery charger that also tests the battery and alternator. The tester said the alternator was good. My battery was putting out about 14 v while running, so that looks good. I don't know what else to look at. And maybe it's all in my head.

Maybe the next test I should do is take a headlight out and stick a digital multimeter on it to make sure the headlights are getting the full 14v.

Has anyone else ever had a problem like this?

[jdl]

With vehicle running, the alternator should carry the load. If it can't, it will pull voltage from the battery. I would check voltage and ground to the headlamps.

[dorlow]

Originally Posted by jdl

With vehicle running, the alternator should carry the load. If it can't, it will pull voltage from the battery. I would check voltage and ground to the headlamps.

How do I check ground? If I pull a headlight and check the voltage with the positive and negative wire, wouldn't I be checking both the positive and ground? The positive 14v is +14v relative to ground, correct? So, if the ground was getting some voltage on the line and say it had 2v somehow seeping into it, my positive should show 12v instead of 14v, correct?

Unless I should just take one end of the meter and stick it to the negative terminal and one to the negative of the headlight and make sure there's no resistance or very little?

I'm not an expert electrician. I know enough to be dangerous.

[jdl]

Voltage to the headlamps is hot all the time. On and off, high and low beam are controled on the ground circuit. You can use a digital multimeter between voltage and ground, see what it shows. I'm like you, I know just enough to get me in trouble. Have a good day.