Low beams don t work but high beams work

Have you checked fuses ? The Instrument panel fuse block , Fuse Block - I/P
LH of the I/P, near the door jamb switch - LF , fuse # 7 HDLPSW 10amp.
In the underhood fuse / relay box - Headlamp power relay , RT HDLP fuse 15amp LTHDLP fuse 15amp.
Battery positive voltage to the headlamp switch is supplied by the HDLP SW fuse in the IP fuse block. When the headlamp switch is in the HDLP position, the headlamp power relay coil is energized. A voltage signal is also sent to the body control module (BCM) signaling that the headlamp switch is activated. The headlamp power relay coil is grounded at G102. When the headlamp power relay is energized, the relay supplies battery voltage to the LT HDLP and RT HDLP fuses. Both low beam headlamps are grounded by the multifunction headlamp dimmer switch in the low beam position through the normally closed headlamp grounding relay in the body relay block to G200.
High Beams-Except ZR2 Battery positive voltage to the headlamp switch is supplied by the HDLP SW fuse in the IP fuse block. When the headlamp switch is in the HDLP position, the headlamp power relay coil is energized. A voltage signal is also sent to the body control module (BCM) signaling that the headlamp switch is activated. When the headlamp switch is in the AUTO or PARK position and the ambient light sensor detects darkness, the BCM produces a voltage signal that will also energize the headlamp power relay. The headlamp power relay coil is grounded at G102. When the headlamp power relay is energized, the relay supplies battery voltage to the LT HDLP and RT HDLP fuses. The RH high beam headlamp receives current directly from the RT HDLP fuse. When the headlamp switch is in the HDLP position, the BCM removes the ground path to the headlamp grounding and DRL relay coils. This allows current to flow to the LH high beam headlamp through the normally closed contacts of the DRL relay. Both high beam headlamps are grounded by the multifunction headlamp dimmer switch in the high beam position through the normally closed contacts in the headlamp grounding relay to G200. A ground signal is also sent to the BCM in order to confirm high beam operation.

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Hi and low beams run on different fuses too. Check the low beam fuse. There might be a grounding strap not making good connection too.

Although not common I have seen both bulbs to be blown I would check that first. But to answer your question the relays are located in the underhood fuse/relay box located on the right rear side of the engine compartment. Also check the 10 amp fuses # 3 and 5 .They are for the high beams . Also this information is for the Ridgline RT. There are 4 submodels and this is assuming they are all the same since you did not provide me with the submodel.

Headlamps
The headlamps are operated when the driver places the headlamp switch in the HEADLAMP position. The LT HDLP and RT HDLP fuse in the IP fuse block, supply battery positive voltage to both the left and right headlamps. The low beam and high beam circuits continue to the headlamp switch. Depending on the position of the dimmer switch, either the low or high beam circuit will now have a path to ground. Ground is provided at G204. The low beam and high beam circuits also provide the body control module (BCM) with both low and high beam inputs. The headlamp switch includes the dimmer and the flash-to-pass switch.
If the headlight switch is left in the HEADLAMP position, the headlights will remain on until turned off or the battery runs dead.
Daytime Running Lamps (DRL)
Any function that turns on the headlights will cancel the daytime running lamps operation. The LT HDLP fuse in the IP fuse block supplies battery positive voltage to the daytime running lamp (DRL) relay coil circuit. The DRL relay switch contacts are connected to the low beam circuit. When the headlamp switch is placed in the OFF position, the BCM will turn on the daytime running lamps. The BCM energizes the DRL relay, closing the switch contacts and grounding the low beam circuit at G204. The DRL illuminate the low beam headlights at a reduced intensity. The DRL will operate when the ignition switch is in the RUN position, the gear selector is not in the PARK position and the parking brake is released. When these conditions have been met the DRL will illuminate.
DRL operation in Manual Transmission equipped vehicles will occur when the ignition switch is in the RUN position, and the parking brake is released.

Probably the dimmer switch . But without testing that would be just a guess . Turnning the headlamps on Any function that turns on the headlights will cancel the daytime running lamps operation..
No ,don't think the DRL relay has anything to do with it .

View wiring diagrams an testing the electrical circuits at the dimmer switch would be the proper way to diagnose .

what fuses were blown and replaced? Theres a TBC fuse under the hood, along with a Headlamp Relay. Theres a R HDLP and LT HDLP fuses, make sure they are getting power, and are good. If the LT HDLP and RT HDLP fuses are good AND getting power, then the TBC fuse and the relay is good. then I would suspect the Hi-Lo dimmer switch bad. The LOW beam ground wire is YELLOW, the high beam ground is PURPLE. see if high beams work, if they do, then I suspect the dimmer switch is bad.

If high beams work and low beams do not, then it is probably the high/low relay. It is part number 15016745 and has four prongs. To test if your relay has gone bad locate the relay in your fuse box. There will be two of these relays located next to each other. One controls the low beam headlights and the other the cooling fan. Swap the relays and check your low beam headlights. If the low beams work you have a bad relay.

Hello, on the van you have a high beam fuse and relay. On the low beam you also have a fuse and relay. Check the fuse/relay panel for a blown fuse controlling the low beam lights. If you do not find a blown fuse have some one to turn the key on and turn on the high beam lights. During this time locate the low beam headlight relay and place your finger on top of relay, have the other person to switch from high beam to low beam lights. You should feel a click in the relay when they make the switch from high to low beam. If not replace the relay and the problem should go away. Hope this will help you.

Thanks

On the van you have a high beam fuse and relay. On the low beam you also have a fuse and relay. Check the fuse/relay panel for a blown fuse controlling the low beam lights. If you do not find a blown fuse have some one to turn the key on and turn on the high beam lights> During this time locate the low beam headlight relay and place your finger on top of relay, have the other person to switch from high beam to low beam lights. You should feel a click in the relay when they make the switch from high to low beam. If not replace the relay and the problem should go away. Hope this will help you.

Make sure the TBC fuse is good in the fuse box under the hood. There is also a Headlamp relay, and fuses marked LT HDLP, and RT HDLP, If the RT HDLP and LT HDLP fuses have power, the headlight switch is good. Be sure battery power is present on both sides on these 3 fuses. If you ground the PURPLE or YELLOW wires at the bulbs, they should light. If they do, the one thing that the high and low beams have in common is the hi-low beam switch and the ground for the switch. The ground ends up at the lower left corner of the dash, under the windshield. The relay is a common relay and you will be able to find another one in the fuse box to swap for testing purposes.

There is normally a diagram printed onto the the inside of the fuse case.