So I'm about to pull every last hair out of my head..

About a month ago after driving in a storm, both hi and lo beams stopped working on my 2000 Accord. All other lights, interior and exterior, are in working order. This is what I've done so far..

Replaced bulbs and checked for any corrosion in the sockets.
Checked the grounds for each headlight.
Checked and replaced both headlight fuses.
Verified both headlight relays are working by swapping them with the horn relay.
Put my switch into a friends accord and it was able to turn the headlights on.
Verified 12 volts going to the switch.
Used a multimeter to discover there is no power going to the fuses under the hood.
Verified that EVERY fuse (under hood, driver side and passenger side) is in working order.

My next step would be to replace the driver side multiplex. Has anyone here had a similar issue?

 

What trim level is your car? On EX trim levels, the circuit goes through the driver's and passenger multiplex control units. On other trim levels, it does not.

Issue may be due to:

• Headlight switch
• Wiring (Blu/Red wire) or connection from headlight switch to headlight relays.
• For EX, Driver's or Passenger's side multiplex control unit

When you turn on the headlight switch, it suppose to send ground (-) via a Blu/Red wire to the headlight relays. When ground is sent to the relays, it energizes the relay coils, and allows power (+) to pass through the relays to the respective headlight fuses, and then to the headlights.

To rule out the headlight switch, unplug the gray 14-P connector from the headlight switch. Use a piece of spare wire and insert one end into the harness side connector terminal no. 7 (blk wire) and the other end into terminal no. 4 (Blu/Red wire). Does the low beams turn on? If they do, then the switch is probably the problem. If they do not turn on, then the issue is probably further down the circuit.