High Beams work, low beams don't

Thank you for the update

 

I know this thread is nearly 2 years old but this happened to me today. I don’t have the equipment or know how to troubleshoot to the extent of some detailed here so I went ahead and took my truck to the dealership service center. They could not recreate the problem. Fuses, switches, everything checked out fine. I had changed the bulbs beforehand (on the way to work early this morning when this happened) and it seems fine now. Did changing out the bulbs solve this once and for al or did it resurface later? Thanks in advance.

 

Changing the bulbs fixed the problem when I had it.

 

Thanks a lot! I appreciate it! Hoping I don't see this again, either.

 

I am having a similar problem. I have replaced headlights and fuses. Did not fix the problem. I put a test light to the prongs on the back where it plugs in and when I switch the high beams on I am able to find the grounded wire, but when I switch it to low beam, all three prongs light up.

 

Low beam prong has voltage when low or high beams are on. High beam indicator bulb gets power through the low beam filament. When you have low beams on does your high beam indicator light up.

Sounds like you need to look at the wiring diagram to narrow down the possibilities. It's not so simple that you can just guess what's wrong at this point.

 

Need some help, having a similar issue but I replaced both bulbs and still no lights. Fuses look fine too. I do live in Washington and there was some water around the connector from the headlights to the wiring harness. Also the headlight indicator doesn’t show up when I put them to the on position but high beams still work

Ended up blowing both low beam fuses. Replaced the high beam fuses with the low beam fuses and figured it out. Maybe this will help someone in the future.

 

Hmmm...are you talking about a 2nd generation? 1st gens don't have separate fuses for low and high beams, at least not on the earlier years. There is just a fuse for left and a fuse for right.

 

Hello. Today is 09 July 2019. Last August I started having this problem. High Beams works but low beams do not. I changed out the bulbs three times. But the problem kept coming back. Then one day I come out to use my truck for work, and it did not start. I had been having the same problem with the lights. So I changed the battery and low and behold, the low beam lights worked. Amazing. Go forward three months and the same issue came back. Battery was still fully charging. I bought new headlight assy for both sides. Had them installed. Worked. Ok. I gave my truck to my sister in Fallon as she needed a vehicle for her day care in Feb. I got it back on the 7th because I needed it to move items after the earthquakes. I was driving at night time for the first time last night and guess what? Yep. Low beams do not work. I am feeling like I need to take it to a shop to have the issue looked at. Amazing. And I put in new lights before I gave it to my sister. Thanks. V/r, Mark

 

Sounds like an intermittently failing switch. But I would definitely make sure the battery cables are removed and cleaned 100% before doing anything else and the grounds. I like to use a pot of hot/boiling water poured onto the battery terminals while still connected to clean them up real well

 

When you replace the bulbs then they stop working are they burned out?

If you touch the glass on the bulb, the oil on your skin can cause the bulb to fail. Something about uneven heating of the glass.

You could also have too much voltage. Have you checked voltage at idle and higher RPM?

 

I use gloves to install the bulbs. I haven't checked the voltage. Good idea. Thanks.

 

Hi, i appear to be having a relatively similar problem as posted about before in this thread. My High beams work, but my low beams do not, and the high beam indicator is always light up, even when it is just in the low beam position. I have tried replacing fuses and lights, and checked that there is power being sent to the headlights as well is the fuses. I’m not really sure what to do at this point

 

did you change dimmer relay? Have same problem and heard this may do it

 

Start here and this will get you going again: Low beams don't work, high beams do,

 

changed switch no burn marks and all wires look good,If I pull relay and jump lights work, also changed relay still no lights

 

hi Eric , i would suspect that the light switch is bad or dirty you would need a wireing diagram to tell which wires go to the high beams to tell whether or not you have power from the switch that goes to the head lights , also i would pull one of the headlights out and check it with a jumper wire to see if it is working or not, wouldnt be the first time ive seen 2 bulbs both bad on low or high beams, also check the connectors that plug on the lights m could be dirty hope this helps.

 

the switch I put in was used so ordered a new one. Since I can flash brights and after looking at wiring diagram it is only logical answer. This is base truck so no DRL so much different diagram

 

Thread is a little old but I wanted to see if I could get help with an issue similar to this one although mine is quite the opposite.
I bought a pair of Morimoto XB LED Headlights for a Tacoma sr5 2021, not too long ago I got a Trd Sport 2022 instead which comes with factory led headlights and I gave the Morimoto XB LED headlights a try on the new truck. When connected to the truck with an adapter all seemed to work fine but as I tested all functions, the following happened...
- When testing the high beam it would blow the fuse
- Blew through several fuses (10,15)

Switched the adapter since there's 2 one for each headlight obviously and no fuses were blown but now...
- When the Stalk is "off" and attempt to use the high beam, the circuit works apparently but in reality it only activates the low beams
-When in "Auto" or "Drl On" the blue jellyfish turns on but no change is made as far as lighting goes
- When in Parking light the high beam circuit activates the low beams same situation when the stalk is on "Off"
-When Headlights are fully on the blue jellyfish lights up on the dashboard but change is made on the lighting (same situation as the "Auto" setting)