Lights working intermittently

[poncho]

Hi, I've recently bought a xj900 ,the light's work fine ie h/light..low beam..running lights and dash lights.
When i go for a run sometimes all the lights go off .
The 15amp fuse is good.
Any ideas
Poncho

[m40man]

Hi, I think my 1st check would be the wiring / connections for the additional lights you mention. Maybe disconnect them & see if the problem stops or not.

If no change, then check the wiring starting with the loom around the headstock area, looking for any breaks / partial breaks. Disconnect connector plugs & inspect them for dirt & corrosion.

[bobh]

Plus clean the contacts in the light switch (what's one of those, he asks, having got used to newer bikes).

Ditto dipswitch, though I'd have thought that would only affect the headlamp.

Whatever, it's almost certain to be a dodgy connection/contact somewhere, just needing cleaning and possibly a smear of Vaseline.

[sledgegreen]

It might pay to spend some time with a circuit diagram, perhaps even drawing the relevant parts of the diagram. You have an intermittent fault which affects a number of different items. It is probably a single fault (a dodgy switch or other component, a corroded wire or a dodgy connection). Whatever it is, it has to be in the parts of the circuit which are common to all of the items which go off when the fault occurs.

It also can not be in any part of the circuit which also serves any item which doesn't go off when the fault occurs.

I suspect that you will find that there is a single supply from the battery to the fusebox. That has to be ruled out, because it also supplies other circuits.

The fuse itself might be dedicated to the lights, or it might also serve other circuits. So, it might be ruled out or it might still be suspect.

From the fuse box, there will be a feed to the lights on/off switch, and from there I think there will be a feed to the dip switch and probably a separate feed to the side lights (and possibly dash lights). You say that the running lights go out, so if I am right we can rule out anything after the lights on/off switch.

I don't have a circuit diagram to hand, so there might be some errors in this. However, I think you probably have a fault in the fuse box or the on/off switch or the wire(s) or connections between the two.

[rustytool]

Divrider is offering a free haynes manual for the 900, see his post in for sale & wanted.

I'd snatch his hand of if it were for a 600.

excellent troubleshooting info there sledgegreen, i shall bookmark this thread.

[sledgegreen]

You are very welcome, Rustytool. Thanks for the compliment.

I should have mentioned in my previous post that any auxiliary lights might be on a separate circuit. They should be wired with a relay, which is triggered by one of the main light circuits - either dipped or main beam. If power to the main beam circuit is lost, the relay will switch off. This means that the auxiliary lights will 'fail', even though that circuit is working perfectly.