No headlight - not sure why

Hi all

I've been playing with the pc800 today and finally got around to checking the headlight. It doesn't light up.

Switch continuity = fine

Bulb continuity = fine

voltage at the socket low beam = 11.5v on low and 0v on high

voltage at the socket high beam = 0v no matter the position of the switch

fuses = fine - all of them

There's nothing in the wiring diagram about a relay of any kind for the headlight. I'm stumped because it apparently passed a safety inspection last fall.

Check the ground, particularly from the bulb socket to the frame via the forks.

Dr. Hess wrote: Check the ground, particularly from the bulb socket to the frame via the forks.

Will do Sunday - wedding tomorrow (not mine).

I did take the starter and high low switches apart and scotchbrite/dielectric greased them. The headlight wiring goes through the starter switch and is interrupted when you push the start button.

They were both pretty gross. I have the kill switch inside and ready to clean up too. If all of the other handlebar switches are gunky, I should clean this one up. Just finished it actually, It didn't want to come apart as nicely as the others, but I got it. It'll go back on Sunday

If your grounds are good, it is also possible to have +12V when you check the socket but zero-ish volts when the bulb is in the circuit. This is caused by a high resistance connection somewhere in the line, such as the switch, a splice, fuse, breaker, etc.

Basically, put your DVM negative on the battery, perhaps via a long jumper wire. With the positive and the bulb connected, start at the bulb and work your way back until you find +12v.

Wow your right no relay....strange indeed. wiring diagram

Update - jumped across the starter switch and headlight switch and got a low beam :D.

Cleaned the grounds anyway.

Still no high beam jumping switches, but the DPO had a brights flick switch on the handlebar. At least I'm pretty sure it was a high beam flicker. I'm going to see if I can find where he tapped in to the wiring and see if there's a disconnect there...

Update update. It lives :)

When I disassembled the kill and high low switches, I didn't see these teeeeeeny little springs that push on the rocker contacts. Therefore, I didn't put them back in after I cleaned the contacts. They both fell out and were on my little work table. Thing is I noticed one of them Friday when I cleaned them.

The switches are correctly reassembled now and they both work perfectly now :D

The culprit in all of this is the starter switch. I put everything back together after a second cleaning and still had no headlights - until I squeezed the starter switch in the middle of its body. Then it all worked momentarily

I squeezed it again and I had contact again. Instead of further fussing with the starter switch, I'll buy a new one. It's still available from Honda.

The kill and high low are also available, so if they give me any more lip, I'll give them a viking funeral like the starter switch will get. That is, when the new one is on the bike and known to work.