[matyivagyok]

Gen 7 celica from 2000. Yesterday evening I was cruising around with her as per usual and everything was working just fine (aside from a fog light but read "p.s." for more info on that). Today I get in the car run a few errands and when I arrive home my mother tells me that my left side low beam isn't working. I get out to check and sure enough it's not working. Then I go over the usual stuff, fuse box: nothing there, all fuses good. Then I took out the bulb and it's not broken visually.
I'm at a loss, don' t know what to do as all other bulbs are working fine.
p.s: my left side fog light was broken too and I was in the process of buying another bulb for it, but when I was testing the bulbs today because of the low beam, the left side fog light came back to life (and apparently it took my low beam in change)

 

[elliotgofast]

You can take the bulb from the good headlight and put it in the bad headlight to rule out a bulb issue. Otherwise, it sounds like a broken or missing ground wire to the chassis. The fog lamp is probably creating the ground circuit and that is why it is sort of working now when it didn't work before. This is called a floating ground because it is finding the path to complete the circuit. You might have to take things apart under the fender wing, behind the headlight, and clean and inspect any chassis ground connections. Another way to test is to back probe the headlight connector ground circuit with a sewing needle or T-pin and use alligator clips to run a wire to the battery ground. That takes the wire harness ground out of the picture to see if it is a floating ground or not. Just to also be certain, use a test light or volt meter and make sure one wire is hot when low beam on and one wire hot when high beam on.

 

[rgarri418]

It's most likely your connection happened to me . Also did u check to 2 fuses in the relay box there are 2 10 amp fuses for headlights in thete as well as the big one ?