Hello there, the low beam for my headlights suddenly stopped working last week on my mazda tribute. I have determined it is not
a fuse, but unclear on the relays. Could a bad relay be causing this, and if so, where would I find it on the vehicle. Thanks

 

Bad fuses or relays will not cause both low beam headlights to not operate. Would lose low and high beams if relay was faulty. Headlights are fused from side to side so if fuse was blown would lose high and low beam on one side only. Improbable but not impossible that headlight bulbs could have both gone out at close to the same time. Otherwise looking at a faulty headlight switch.
Power/voltage in to the headlight bulbs is from the White w/ lightgreen stripe wire at left headlight and Dark Blue w/ LIghtgreen wire at right headlight. Providing a ground to either of the other two with headlight switch on should power up the low/high beams respectively. If they do light then the switch is not providing this ground path.

 

Thanks for the info babyhuey. Just so I'm clear, when you say the headlight switch, are you speaking of the little
arm on the steering column where you turn the lights on and off?

 

Yes.