why does one headlight not come on fully, when the other one does?

Question

i have replaced the bulbs and still one headlight doesnt come on fully, its stays on dipped mode! it seems a lot of cars i see on the road do this too, why?

Answer 1

there must be a bad connection, not getting full voltage to the second headlight...

Answer 2

By the terminology you are useing I am guessing we are talking European automobiles. By "dipped" mode I am assuming you mean low beam which, if on the drivers side would possibly mean that this is something new where the brite function of the light only works on the passenger side as it is furthest away from oncomming traffic. Another reason may be that the headlamps are the newer "projector" design and eadh headlamp is aimed differently to the extent that one may appear to be "dipped". Check your headlamps, in both the "dipped" (low beam) mode and High beam mode, from several different angles to ensure that this is not an normal aiming condition. If this is not the case then check the wiring on both headlamps to see if there are the same number of wires going into each headlamp. If this is the case then you have a problem in the circuit on the "dipped" side. If not then the answer may be that the regulations governing headlamp operation have changed in your area. In any case, check with the dealership to be sure.

Answer 3

Each head light usually has two bulbs, the side light (a little 12v job) and a large halogen lamp. The side light is a back up. The light responsible for both the dipped beam and the full beam is the big halogen lamp and can be controlled in a number of ways. Some lamps have a dual filament (this is true of some bulbs used as rear lights and break lights: the bright filament can blow whilst the main filament will still function).

Answer 4

You have a bad ground wire in the electrical harness leading to the headlamps. Go to the back of the headlamp and carefully jiggle the wiring a bit and see if it changes in brightness. Follow the wiring and you'll probably find a wire with a round terminal and a scew going through it. Loosen the screw then retighten.
That will usually cure the problem.

Answer 5

either worn out multi function switch(headlight switch stalk assembly on the steering column- common problem) or bad connection(less likely)

new switch is about 60 bucks, they have little copper contacts in them that wear out, it takes about 45 minutes to replace one, have had to do it three times so far on a 98 cavalier an uncle of mine owns, they wear out, it happens, he drives it alot, thousands of miles a months




good luck

Answer 6

Bad ground somewhere in headlamp circuit.

Answer 7

Loose connection?

Answer 8

fuse