Mick Smith
New member
I have a '79 CB550f, I can't get the headlight to switch on to full beam. I checked the fuse box and the previous owner has installed fuses that are above what they're supposed to be- for instance the 7a fuses were replaced with 15 ones, and where the 15a fuse should have been someone had stuck a 35a fuse there. Not the kind of thing you normally check when you buy a bike and I've only done a few miles on it. The main beam was operational when I got the bike and it's sat covered in a dry garage for about four months, I've run the bike maybe fifteen times in that space of time, but it's stopped working somewhere along the line.
Anyway, is this fuse situation this likely to be the source of my problem or am I missing something even more obvious? I put standard value fuses back in, nothing changed. I then checked the bulb which looked fine, but I removed and replaced it anyway- no joy. At some stage someones replaced the standard fitting bulb with a modern three pronged halogen bulb, the wiring looks to be original although it's hard to tell. The park lights and low beam are running off a separate bulb located below the main light so they're completely separate.
Am I right in thinking that this has happened because of the non standard value fuses that were installed previously? Something somewhere has obviously bitten the dust but I have no idea what it'd be, I thought maybe it's the switch itself but it was working fine a few months ago and has been used little since then.
Ah, frustration...
Anyway, is this fuse situation this likely to be the source of my problem or am I missing something even more obvious? I put standard value fuses back in, nothing changed. I then checked the bulb which looked fine, but I removed and replaced it anyway- no joy. At some stage someones replaced the standard fitting bulb with a modern three pronged halogen bulb, the wiring looks to be original although it's hard to tell. The park lights and low beam are running off a separate bulb located below the main light so they're completely separate.
Am I right in thinking that this has happened because of the non standard value fuses that were installed previously? Something somewhere has obviously bitten the dust but I have no idea what it'd be, I thought maybe it's the switch itself but it was working fine a few months ago and has been used little since then.
Ah, frustration...