NO headlights (except in reverse)

[twoup1200]

Greetings! This is my first post since joining the group. Thanks in advance for your help!
I have a 2007 GL1800. On the last ride I noticed that I had no headlights, bright or dim. Everything else works fine.
I found a service manual on line and started digging in. Here's what I know.
1. Bulbs and wiring from the lo and hi relays are good.
a. I removed the relays and jumpered the contact side in the relay sockets. Lights came on.
2. The Lo relay works fine when reverse button is engaged. Lo lights come on in reverse. I understand that this is a separate circuit, separated by diodes, to energize the lo light relay when in reverse.
3. I think I understand the relationship between the start button and the reverse button.
a. Start button will shut off the lights when starting the engine. This function is bypassed when the reverse button in engaged. So, when in reverse, the lights stay on when the start button is pressed.
4. I've checked power to the dimmer switch. This switch really only turns on the brights. Dims should always be on.
a. There is no power at the dimmer switch. I could actually get my meter on the wires at the switch. Both wires to ground had no power.
b. All fuses are good.
5. I've verified that the reverse and start buttons aren't stuck part way. Both stroke fine.
6. I've opened the housing and sprayed contact cleaner into the start and reverse switches. No change.

So the probable culprits are the connector, start button, the reverse button or possibly diode D21. (I doubt it's the diode). There is only one connector between fuse 9 and the start button, I think it's P12 G? I don't have the drawing in front of me right now. I was unable to get a meter on bare wires on those switches.
Trouble shooting those things would be easy if I knew where the connectors and diode were, or if the solder connections at the switches were available. I know the connector numbers, just don't know where they are. Plus I have a sinking feeling that the connectors are impossible to get to.
Thanks for your help.

[GoldWingrGreg]

Sorry ... I don't have a Service Manual in front of me. But I thought that the low beams shut off when the start button is pushed in. As for the location of connectors. A Honda Service Manual has pictures of those in either in front of, or behind the index. Sometimes it is easiest to go to the index, find "kill switch" and there should be a page number there to find the picture. In either case, the kill switch assemblies connector is found in a white cage in front of the right front pocket. The reverse regulator is found under the seat. It's attached to the left side of the front rear fender between it and the left rear saddle bag. Have fun getting access to it. Frame is all around it.

[tamathumper]

On my 2003, about every four years, I will lose the headlights. A thorough cleaning and exercising of the Start button is all it takes to restore them.

[twoup1200]

Thanks guys. GoldwingrGreg. The headlights should shut off when the start button is pressed unless the reverse button is in. Apparently some states require the headlights to be on when the bike is in motion. Silly as it is, reverse is in motion.
I’ll look for the connector on the right side.
Thanks.

[GoldWingrGreg]

Thanks guys. GoldwingrGreg. The headlights should shut off when the start button is pressed unless the reverse button is in. Apparently some states require the headlights to be on when the bike is in motion. Silly as it is, reverse is in motion.
I’ll look for the connector on the right side.
Thanks.

Thanks for the reminder, and of coarse the headlights need to be on when using reverse ... I should have known that

[Techdude2000]

This is simply a dirty starter button switch, burned contacts, or a blown Head Main fuse, #14. Check the fuse. If it’s good, then spray a bunch of contact cleaner into the crack at the top of the starter button switch and work it a bunch. If the cleaner doesn’t get it, the switch may need to be replaced. The diode would only kill the low beams, it has no function in the high beam circuit.

[WingAdmin]

Believe it or not, this is not the first time this problem has come up here in the GL1800 forum. You can see it here: 08 GL1800 headlights only work when in reverse

[twoup1200]

Thanks for the reply. I did try to search before I posted. Just didn’t come up with that thread.
I’ve cleaned the switches and checked all the fuses.
I can get a meter on the soldered terminals at the dimmer switch. No power from there to ground so I don’t think it’s a ground issue. Has to be a power loss issue. Probably due to a connection or broken wire? I just can’t face removing the faring to get to the connectors. If I ran the world every connector would have an easy access panel

[Rambozo]

Thanks for the reply. I did try to search before I posted. Just didn’t come up with that thread.
I’ve cleaned the switches and checked all the fuses.
I can get a meter on the soldered terminals at the dimmer switch. No power from there to ground so I don’t think it’s a ground issue. Has to be a power loss issue. Probably due to a connection or broken wire? I just can’t face removing the faring to get to the connectors. If I ran the world every connector would have an easy access panel

You don't need to remove the fairing. The connectors are just under the right side fairing pocket. The pocket is the access panel you wanted.

[Techdude2000]

Thanks for the reply. I did try to search before I posted. Just didn’t come up with that thread.
I’ve cleaned the switches and checked all the fuses.
I can get a meter on the soldered terminals at the dimmer switch. No power from there to ground so I don’t think it’s a ground issue. Has to be a power loss issue. Probably due to a connection or broken wire? I just can’t face removing the faring to get to the connectors. If I ran the world every connector would have an easy access panel

Ok, so here’s the schematics for the headlights for your model. Like Rambozo said, you only have to remove the right side fairing pocket to reach the connectors in the white frame to the front of the pocket’s hole. C16, 17, and 18 are under there. Before you get under there, check for power at the starter button switch wires, you only have to drop the lower half of the control pod down to reach them.

[twoup1200]

Awesome. Thanks for the info and pics. This is a great site. Thanks again!

[sticks.df]

And the solution was.....?

[tamathumper]

For Sale: GL1800, many farkles, good tires, has "Reverse Headlight" Mod

Maybe the OP found the solution in the linked thread, which pointed to corrosion in the C18 connector under the right cubby pocket?

[sticks.df]

I hate when persons don't post the fix. Can't help the next one mahap fix theirs.

[twoup1200]

Sorry guys. I agree it’s rude to not post the outcome. I had to leave for a work assignment overseas. My time is very limited right now. I appreciate the advice very much and will let you know what I find. Till then, thanks.
BTW. I did take the right side handlebar switch housing apart but it’s tight in there and I couldn’t get to any contacts to take voltage measurements. The wires just disappeared into the switches.