The 20 Amp fuse for the head lamp circuit on my 2001 ST4S keeps blowing. The strange thing is when the headlamp is on the Rev counter stops working! Switch the headlamp off and the rev counter works again. After replacing the fuse last time the headlamp stayed on for a few minutes and blew the fuse as soon as I put the main beam on. Now I don’t know if this is coincidence or the extra current from the main beam blew the fuse. But what I do know is the rev counter restarted when the fuse blew. This is the only occasion I can definitely say the fuse blew with the main beam, on the past few occasions it just seemed to go after a few minutes. Any one got any ideas what could be going on?
Peter Don't know the ST4S but had a quick look at a wiring diagram and need to look some more. A common component between dash/rev counter and headlamps is the headlamp relay. I would think it will be at the head of the bike in the headlamp/ignition switch area. Take a look at it to see if its in good condition and the connections for a start. Side lights Ok? When you switch on the headlamps can you hear the headlamp relay click (you'll need to listen carefully at the headlamp area)? Flash/Pass button working Ok and not giving you issues? The relay is activated by the dash if its damaged it might be a problem If I can get some time I'll look at the wiring diagram and see if I can see anything......no guarantees mind John
Worth checking the headlight bulb connections. Low beam is completed inside the rubber boot but the Hi beam has a fly lead which is usually connected outside of the boot. The insulating cap on this can come loose and expose the connection. If it touches the headlight housing, then the fuse blows. check also the large block connector on the LHS of the front subframe. This can suffer with corrosion and lead to alsorts of issues.
Thanks for the replies, that's a few things to check. Probably be the weekend before I get chance to look again.
