Low beam problem

[benny]

Riding with JB the other day he noticed my left headlight wasn't working, so I got off and checked it and realised on low beam the left doesn't work, he told me it's a dual filament bulb so It's one bulb that does both high and low but one of the filaments must of gone. So on my way out today I went and got a H4 55/60W bulb (expensive from Halfords) but I was just looking at my headlights and realised JB was wrong, the low beam seems to use the two little bulbs underneath the main big H4 bulbs, my right light has a large round orange bulb working fine in this slot whilst my left has a little white LED that is flashing rather than constant and isn't very bright. Was JB right? should the two big bulb also light up on low beam but just dimmer, and any idea why these LED is flashing? I've tried giving it a wiggle and still has the same problem.

[gavins]

Normally it's dual filament so yes the main lights should come on on low beam. The standard spec bulbs are 35/60W and are NOT standard H4 fitment. They're a H4R fitment (i think) and are a special honda item at £18 a pop.

http://www.davidsilverspares.co.uk/VFR4 ... rt_150906/

You can fit them by cutting the tabs off or modifying the fitting but running a pair of 55/60w bulbs without a relay will eventually melt your switchgear.

This assumes that you are running standard, unmodified, headlights.

The smaller bulbs underneath the main beam are a little sidelight that comes on when you have the headlight switch in the middle position (and with the headlights), along with the tail lights. It sounds like one of these has been replaced with an LED for some reason? They would usually be white/yellow light filament bulbs (i forget the rating but it's pretty low).

[benny]

Ok, we'll nether main bulb is coming on at low beam, Alex said I have the relay mod (bunch of wires near the radiator) so I got the 55/60. If one was blown would that give a reason for both not to work? Or is it possible that both have now gone since JB pointed out that one of them had?

[gavins]

No, normally one filament being broken would not effect the other headlight.

Have you got an electrical tester with small probes?

If so, take the plug off the back of the bulb, turn the low beam on and check you get 12v across 2 of the pins (i can't recall off the top of my head which is for low and which is for high and i'm at work). If you've a haynes, check the wiring diagram for the color of the wires.

You can take the bulbs out and visually inspect the filaments to see if one is broken. Sometimes it's not obvious unless you gently flick the bulb to see how much the wire vibrates.

[benny]

So checked the fuse, no problem. Took the connector off the bulb, the Hugh beam is reading correctly but I'm getting no voltage when on low beam, the switch isn't stuck and the relay is installed ( not by me) so attempting to check/fix the relay now

[benny]

Found the problem, dodgy scotch lock, dads a car electrician and thinks he's got a better way of doing it so that's going to be the first project in the new shed