Why both headlights not work on low beam but work on high beam?

Answer 1

There could be a fuse for each low beam light either under the hood or under the dash. If not, then prob both low beams are bad.

If you have daytime run lights, the following may be of help.

There is a daytime running light module that controls both low beams and the daytime running lights. The low beam bulbs may be OK. The high beams will work fine as they are not controlled through the module.

It may be possible to disable the daytime run lights by cutting the yellow wire going into the module and then connecting it to ground. Tape off the other end.

Check the bulbs or replace one at a time to see if it works,hope this will solve your problem.

Bad bulbs?

Bad switch (high/low)

I just fixed this problem , it was my daytime running light module

I replaced the DRL module and still had this problem.

A good place to see how to disable DRL is here;

The problem for me was a clip with about 6 wires or so that plugged into the fuse box (located under the steering wheel. 3 Phillips screws had to be taken out to get the panel off that was covering the fuse box, DRL, etc.)

I simply unplugged the wire clips from the fuse box one at a time until I found one that looked burnt and melted up. There was only one wire that was blackened and one corresponding pin at the fuse box side that was black.

I took a small strip course sand paper, folded it in half and carefully sanded the black off the male and female ends. **be very careful not to bend the pin or it could break off!

I then sprayed electric contact cleaner on the cleaned areas (may not be needed) and let it dry for a min.

I squeezed a little dielectric grease into the female end of the clip to help make a better connection and reduce heat in the future. (may not be needed)

I then took a small strip of thin (approx 1mm thick) metal and cut a strip about 1/4" long (you could use a verity of metal, foil and wire for this) that would fit in the female hole to make a tighter fit and better connection. Heat may have melted some of the plastic leaving a loose fit. I bent the very end (about 3mm down) at 90 degrees so the small piece of metal wouldn't go all the way in the hole when plugged back into the fuse box (The dielectric grease helped hold it in place).

** Make sure its not to snug or it could bend the pin.

I then carefully plugged it back in (it was very snug, but it went in OK). I tried the headlights and the low beams worked perfect and so did the high beams.

Summarized; it was a clip at the fuse box not making a proper connection causing arching (sparking), causing blackening and eventually no connection at all. Fix this by cleaning the black off and making sure its a snug fit when plugging it back in or it will happen again over time.

** If this doesn't make sense to you, you probably shouldn't try it. I hope this is more helpful then confusing.