Poor earth ?

[alan g]

A little help please lads.
Over the winter the firestorm has had a little love and attention; new CCT’s oil and plugs, all the usual stuff.
There is one problem though… when you pull the brake leaver the lights come on! Must be a poor earth somewhere: but were do I start looking?
Is there a typical earth connection point that would cause this problem?
The fairing has been off and so has the air box and thermostat housing,

Thanks

Alan

[Pete.L]

I don't know of any common problems which would cause this but (just a thought)
Could you have trapped any wires when putting the fairing back on? or maybe the loom was too close to a bolt when you put it back together, trapped it under the tank.
I take it you mean the front lights are coming on and not the rear. If it's the rear it's probably the brake light bulb filament has cracked and dropped down onto the rear light filament. Two new bulbs would fix that and you would have checked that first before posting

Pete.l

[tony.mon]

A possibility is that you have a short across the leads fro the headlamp flasher shorting with the front brake light switch.
It'll be in the connectors or wires form the LH bar dropping down to the wiring harness, most likely.
Pop the fairing off and inspect closely.

Just from memory I seem to recall that the wires form the brake switch are just two leads with bullet connectors- you haven't plugged them in the wrong place, have you?
One way to check this would be to see if the brake light comes on when you pull the front brake on.

[alan g]

A possibility is that you have a short across the leads fro the headlamp flasher shorting with the front brake light switch.
It'll be in the connectors or wires form the LH bar dropping down to the wiring harness, most likely.
Pop the fairing off and inspect closely.

Just from memory I seem to recall that the wires form the brake switch are just two leads with bullet connectors- you haven't plugged them in the wrong place, have you?
One way to check this would be to see if the brake light comes on when you pull the front brake on.

Thanks Tony I will have a look now. It’s the front small position light (side light) that’s coming on along with the instrument lights, when the brake is pulled.

At least it gives me something to do on a wet day!

Alan

[sirch345]

the brake light bulb filament has cracked and dropped down onto the rear light filament.

Pete.l

I've had that catch me out before Pete, although on a car. It gave me a right headache before I finally twigged what it was

Definitely worth checking as it's easy to do.

Chris.

[alan g]

I’ve been checking the connectors under the instrument cluster and cant find the fault.
It’s the position light and instrument light which comes on when the front or rear brake is activated, the live to the position light is picking up power when the brake light comes on. The position light does not glow at full intensity when the brakes are used.

[sirch345]

I’ve been checking the connectors under the instrument cluster and cant find the fault.
It’s the position light and instrument light which comes on when the front or rear brake is activated, the live to the position light is picking up power when the brake light comes on. The position light does not glow at full intensity when the brakes are used.

You've not said if you've checked the filaments in the rear light bulbs yet, as Pete recommended

Chris.

[alan g]

I’ve been checking the connectors under the instrument cluster and cant find the fault.
It’s the position light and instrument light which comes on when the front or rear brake is activated, the live to the position light is picking up power when the brake light comes on. The position light does not glow at full intensity when the brakes are used.

You've not said if you've checked the filaments in the rear light bulbs yet, as Pete recommended

Chris.

As Pete said “if it’s the rear lights” but it is not the rear lights, it is the front position light.

I have checked the rear lights, with and without bulbs, and the fault is still there.

Thanks
Alan

[tony.mon]

Is it the old or new type instruments?

As I haven't got the new type to play with I don't know if the connectors are the same, and don't want to set you on the wrong track.
From what others have said in other conversations the connectors are different.

[sirch345]

As Pete said “if it’s the rear lights” but it is not the rear lights, it is the front position light.

I have checked the rear lights, with and without bulbs, and the fault is still there.

Thanks
Alan

Alan, you've missed the point What happens when this occurs is that the top filament (brake light)in the rear light bulb breaks, it then hangs down onto the next filament making a bridge for the current to be passed into the rear light and position light wiring once the brake is applied (using front or rear lever). It will also power up anything else connected into that circuit.

But if you've tried it with the bulbs removed from their holders then it won't be that. But if you've just removed the bulbs from the rear light and left them in the holders then this could still be the problem.

HTH.

Chris.

[tony.mon]

Here's a way to check earths to things like lights, indicators, electrical component bodies etc.

Take a wire and connect it to the battery negative. make the other end into a probe, one from an electrical tester is good, a thin nail soldered on works just as well.
Turn the ignition on, check that the kill switch is in the run position.

Touch the ground contact (or body of an electrical component) and look for a small spark. There shouldn't be one, because the lead should already have a good ground, i.e no potential difference.
Any spark; there's your problem.

Obviously, this is best done with a meter set to resistance, but this method works when you're away from tools, in a lay-by or on a camp-site.

You need to recreate the problem while you're testing, so if it's a problem when the front brake is pulled on, then you need to pull the brake on while testing.

Next, because the front and rear brake lights are connected, you need to isolate which part of that circuit is causing the problem, so disconnect the rear brake light connector and see if the pilot light still comes on when you pull the front brake lever. If it does, then the rear bulb and wiring from the connector onward isn't your problem.

Next, reconnect the rear connector and disconnect the front one. Test again.
If the problem's still there this time you have a short on the harness somewhere.
Otherwise it's a duff front brake switch.

Either your front brake switch or sidelight isn't connecting properly; there aren't that many wires to choose from.

Happy hunting.....

[alan g]

Thanks Tony and Chris
I will go back in and have another look.

If I find it I owe you both a pint.

Alan

edit: by the way, its an early one 97

[alan g]

Success… I tried a mutimeter on everything (even though I can’t use it properly) nothing worked! Tested the switches the bulbs the holders… nothing, then when I pushed a wire from the battery earth into the rear bulb holder… bingo, but the good news was that when I remover the second wire, it continued to work probably! It must have been a poor connection at the earth terminal at the back of one of the bulb holders to the rear light.

Thanks again for all your help. Ironically the only part I have not had apart this winter was the rear end, and that’s were the fault was.

Alan

[Pete.L]

Well done Alan
I must admit, when you said it was your side lights coming on I really though you had either sorted something or connected something wrong on your reassembly.
Good on you Bloke ,Good find

Pete.l

[alan g]

Well done Alan
I must admit, when you said it was your side lights coming on I really though you had either sorted something or connected something wrong on your reassembly.
Good on you Bloke ,Good find

Pete.l

Thanks Pete, it did feel good when I found it!

Thanks for all your help.

Alan