2000 Chevy Blazer, all of a sudden the headlights got super bright! Every bodies flashin' their headlights and shootin' me hand signals. I checked the adjustment and it's O.K. I also replaced both bulbs but they are still too bright?? Ch'd voltage at batt. - 14.2. I'm baffled!

 

Is it the high beams or the low beams that are too bright?

 

14.2 v at thebatt posts is quite high (I understand you measured them when engine is iddle). 12.8-13.2vis the idea if I recall correctly. If beams areproperly aimed and used,maybe the lights are bright in excess due to that overvoltage condition.

 

My truck idles at 14.4volts. when off you should be around 12volts.

Has this been an all of the sudden type of thing? Has something happened that has caused your highbeams to always be on? How did you verify your headlight aiming?

 

Manual calls for 14-15 volts at the batt. at idle.

 

Low beams...

 

This has been an all of the sudden type of thing. The problem is with the lowbeams. I'm sure the alignment is correct.

 

Check all of your headlight harness grounds and relays. Most people are looking for more light on the road. Also did you change style of bulbs, ie: hyperwhite blue tints etc. Sometimes people will perceive the color blue as brighter since it is closer to daylight and with all the rest of the horizon black it is just a matter of perception.

And there is an easy way to double check your aim with out taking it into a shop. Find a light colored flat wall and mostly level parking lot, move the front bumper away from the wall about 25ft, find the centerline of the truck. Then measure to the height center line of the headlight, take that measurement and go to the wall and put a piece of tape or the quickest is to measure the light's output on the wall to see if it is below the headlight centerline it should be min 3" below up to a maximum of 6" for a lifted vehicle...same thing for foglights either factory or aftermarket they should be mounted below headlights prefered under bumper and projecting light below the height centerline of mounted light at 25ft (make sure that if the fog light is labeled "top" that the lens is correctly positioned if mounted under the bumper)...

 

I forgot: measure the voltage not at the batt posts but in the bulb. Maybe too much voltage.

 

Really isn't such a thing as too much voltage to the bulb. Maximum life is actually experienced at something like 14.2V. When I get my relay setup finished, I'll have 14.4V-14.6V at the bulb and will be lovin' it!

More than likely you either have something keeping your highs on or you have an alignment problem.