I've got a 1999 m900 - bought a couple of weeks ago 2 days after passing it's MOT (!) noticed the dip beam wasn't very bright and on checking high beam works but dip doesn't Swapped the bulb out for a known good bulb and still no dip beam (put the builb onto another bike and dip beam works) Checked the headlamp connector - I'm getting 12v on high beam (black/yellow) but 0v on the dip beam (white) Are there any connectors hidden anywhere that I might need to clean etc ?? Suggestions please !
Sorry for the grainy image, but I think this is correct off the net, not at home so can’t look at any manuals . I didn’t think there was a relay used here and above confirms this, if you look at item 11, dip beam wire looks like it was coloured white on this diagram, and there are at least two connectors en route, that could have light corrosion (npi), or even a wire break. Although unlikely, The latter does feature more on your monster than the SS or most of the bikes of the era, because of the tight bunching as it passes around the headlamp area.
Check for continuity of the white wire between the LH switch (pin G) and the headlight connector. If that is ok check continuity between the brown/black wire (pin F) and the white wire of the LH switch when dip beam is selected. It should be almost 0Ω and no connection when high beam is selected. If no connection when dip is selected then the switch is faulty. Not much more to it really apart from checking for corrosion at the connectors.
Only thing I didn't add was that switch might be faulty, but decided to assume at least a modicum of sense on here - it's all there on the diagram..
Ok - I was going to let this slide into the past without saying anything about my stupidity but since someone replied... I was using the Haynes manual for the wiring diagram - which doesn't really show how the switches work in a traditional sense. To get the bike through it's IoM test I put a wire between the side light and the dip beam and it got through it's test. A couple of days later I sat with a meter to work out what was happening, seeing if I had a cable break etc etc.. Undid the connectors, checked the switches and all seemed fine, no resistance when the switch was on, open circuit when it was off - noticed the Haynes manual had a couple of things not quite right on the connectors but worked past that. Ended up taking the switch off and looking inside, working out what was going on from the wiring and then I found my mistake. I'd been putting the light onto side light and not onto "on"... I had thought the light switch was Off / dip beam / high beam. I hadn't realised it was off / side / main with a separate switch for dip / full beam. In my defence the guy that borrowed my bike did exactly the same thing and had also been riding round with it on side light.
