For some reason my headlights are not as bright as they were or should be. I am having trouble seeing at night on dark streets unless I turn on the brights. They are also not up to par.

Nothing was done to it that I can think of that might cause a problem with the lights as far as I know. An upholstery guy did disconnect the battery while replacing the master switch for the windows, but nothing else as far as I know.

Does anyone have any clues as to what could cause the lights to suddenly go dim?

Thanks in advance. Any ideas appreciated.

 

Is your alternator light on? Or, have you checked the battery voltage when the engine is runnning? It should be in the range of 13.2 and 14.0 (or more) volts... and should drop down when you shut off the engine. If not, the alternator may have failed.

 

The alternator light is not on and the car starts up with no problems every time. Driving with the lights, heater, stereo all on at the same does not seem to weaken the battery either.

How would I check the alternator voltage?

Thanks

 

I found on purchasing my V40 that the standard headlights and the specified bulbs offer disappointing performance especially notable on dark, unlit streets at night.

Forums are full of posts from members who wish to or have upgraded their lights which seems to indicate an across all or most models problem.

More recent models fitted new with HID's and LED's never get complained about at all.
Upgrade with brighter output bulbs or convert to HID's if it really bothers you enough.

 

with a volt meter.

park car for a few hours or overnight. read battery voltage cold, ideally its 12.6V or so. start car, read voltage, it should be about 1-1.5 volts higher. if it is, your alternator is working.