Low beam fuse

If you have already replaced the switch and checked the connections, there could be a few other possible reasons for the low beams not working:

1. Relay issue: The headlight relay controls the low beams. Check if the relay is functioning properly, if not, replace it.
2. Fuse issue: Check if the headlight fuse is blown, if so, replace it.
3. Wiring issue: There may be a problem with the wiring between the switch, relay and lights. Inspect the wiring for any damage, such as frayed wires, loose connections, or melted insulation.
4. Ground problem: Make sure that the ground connection to the headlight is secure.
5. Light bulb problem: Finally, check if the low beam light bulbs themselves are functioning.

If these checks do not solve the problem, it may be necessary to take your truck to a professional mechanic for further diagnosis and repair.

i don't know. perhaps having both beams on that long may draw too much electricity. please repair the high beams
so they light without delay. an auto wrecker yard might let you switch out parts from one of their used vehicles.

this could be a bad ground. Check all connectors for burns or loose conections and go ahead and change the fuses. they may appear to be good and be bad.

Hi Every single time I have had a failure of low beam in a headlight without failure of high beam, it has been because the lamp bulb or halogen lamp module has reached the end of its serviceable life, not because of any wiring problems. Low beam burns out first because it is on the most. If low beam is lost simultaneously in both headlights, I would check fuse first, then the headlight switch. If low beam is lost on one side only, it is almost always going to be due to the bulb or lamp module needing to be replaced. In that case, replace them in both headlights because the other one will be going kaput in short order, as well.Also if you already replaced the fuse and bulb check the headlight dimmer control switch.
Thanks for using Fixya.

CHECK THE BULBS FIRST! TRY REPLACING WITH A NEA ONE ON ONE SIDE, AND TURN LIGHTS ON, IF YOUR LOW BEAM LITES UP, REPLACE THE OTHER ONE! IF NOT THERE COULD BE A WIRING PROBLEM TO THE LOW BEAMS

Your dimmer switch is bad (lever used to flip between hi/low beams) they're only plastic and they go bad. Before you change check fuses, buy I highly suspect dimmer switch.

Did you check the fuse for the low beams? The high and low are on seperate circuits..
Good Luck...

when the low beams quit try switching from high to low and back and see if low beams stay on, if they do it may be the dimmer switch, if that doesn't change anything suspect the headlight switch.

To start ensure that it is not just a blown fuse. If that is not the problem, then you need to read voltages at the back of fuse box, to check if there is volts on wiring from fuse out to light when switch is on. If there is no power you localize the problem on wiring from light switch to fuse box. In this case you may need to take apart the steering column to repair wiring harness (switch has already been replaced).
If instead there is power getting to light fuse, and power out from fuse box to light, then test and repair the wiring to lights from fuse box, if you do not find the problem you may need a rebuild. This can be done by a mechanic or by a car electrician.

Hi Rich Million,

Check the bulbs for the low beam problem and if they're ok, check the fuses under the bonnet (hood) which are found in the fuse box. If you've already checked those, go to the fuse box inside the vehicle.

Still no luck....remember that there are fuses and relays inside the cabin behind the kick panel.....You may find that there is a problem with the main fuse box.....If you drive over rough terrain, check the connections under the main fuse box....even if your roads are all smooth, it's still worth checking.....

Regards Johngee10