Thanks Redbull-1. Unless someone comes through with a spectacular solution, I'm planning to get a fuse/relay box from a salvage car for $75 and see what happens. I'll report back to this post to let folks know how it turned out.

 

Just one more idea...

If the bulb or ground was bad, or the circuit shorted, would that mean I'd get zero volts at the fuse because the circuit was incomplete? The bulb is brand new and even the old bulb has an intact filiment, but I want to look at all options before replacing the fuse box.

Ideas appreciated.

 

It really depends how you test for voltage.

Use a known ground (I like valve cover bolts) for the negative volt meter lead. Then use the + to test the socket for the fuse (remove fuse and test both pins of the fuse box). One pin on each fuse should have 12V.

Take note of the 12V side of the fuse. Then use the - meter lead on the side of the fuse that had no voltage. Use the + meter lead on the known 12V.

If you do not have voltage on the driver's side fuse, then you might want to look under the fuse box for a problem.

Let us know what you find with both suggested tests.

 

You have an open circuit (as opposed to a short); which means the normal path of current is interrupted.

As described in post #8, the relays receive battery voltage at all times. The grounding and operation of the relays are controlled by the multiplex system (i.e., the MICU controls the opening and closing of the relays to operate the headlights).

Looking at the circuit diagram, power (+) to the under-hood fuse/relay box (which flows to the relay control module) comes directly from the car battery. The car battery is grounded on the chassis at location G1 (right next to the battery).

With that said, to answer your question regarding whether a bad bulb or ground would cause zero volts at the fuse (No. 1). No. Although, the left headlight bulb requires ground G301 to work, the relay control module doesn’t require ground G301 to complete the circuit to operate. Similarly, a bad bulb wouldn’t cause no voltage at the No. 1 fuse.

 

This link shows the headlight (USA model) circuit, with power going through the relay control module to the No. 1 fuse.

http://ww2.justanswer.com/uploads/1s..._215557_11.gif

 

Well, this is embarrassing...

The replacement bulb I put in was a 9005, which is what I thought the book at the store said I needed (then again, didn't have my glasses).

After PAHonda's suggestion, I decided to do some more troubleshooting. I found that fuse 1 had voltage if I probed the passenger side of the terminal and put the other probe to ground on the strut tower. SO that gets me back to thinking about a bad ground. I test the circuit for continuity and get none.

I go to probe the connector again and discover that the bulb/connector doesn't seem seated properly. Aha! Maybe just not fully connected! Nope. Had the wrong bulb. Actually needed the 9006.

Finally do something I should have done at the start - I swapped the headlight bulbs. TaDa! I now have a driver's headlight and no passenger. It was simply a bad bulb followed by the wrong replacement. I suppose we've all gone down a rabbit hole on wild assumptions before discovering it's not even a rabbit we're seeking.

Sorry to have wasted folks time, but I did still learn a few things about my car and electrical troubleshooting in the process. I figured by coming back and wrapping this up, something might be helpful to others.

I'm an idiot, but I'm now a happy idiot with two headlights.

 

I am having the same trouble. I have a 2006 Honda Accord EX 4 cyl. The driver side low beam is out. I bought the 9006 replacement bulb, but when I try to install it, it does not fit. When I look at the old bulb, it is listed as a 9005. I bought the 9005 bulb, it fits, but the light does not turn on. Now I am completely confused.

 

Did you go through the checks that were suggested all through this thread? In the end, Techvegas had an incorrect bulb, but maybe YOUR car's problem is actually a fuse, wiring, or a ground connections. With those checks, you should probably start a new thread & tell us what happened when checking those things.