Yamaha TRX850 Enthusiasts Forum

My LHS switchgear now seems to be playing up (as well as the rear light, but thats another story...)

When I put the lights on main (not full) beam, the rear indicators glow gently.

When I put the indicators on, the headlight flashes gently too.

This is all with the ignition on but engine off.

WTF is going on?

The switchgear is off the handlebars but still connected up: it doesnt earth through the bars does it?

Is the battery getting flat?

Mate, auto electricity is like chinese geometry...but it sounds like a bad earth. from my limited knowledge.
Where it is earthed to... can't know.
Probably not a lot of help, but maybe 2 heads etc.

Defo bad earth, I am trying to find a copy of a wiring diagram to steer you in the right direction, as a start point check the connections that lead from the main earth lead to the loom(and any points en route)
If you have a multimeter check out the values from the earth of various light units back to the battery negative you should be looing for values of around 0.1 - 0.01ohm make sure the meter is on that kind of range setting, if you see the meter reading something like 100's of ohms or it goesoff the scale on a negative part of a circuit then that is likely to be the problem.

Not checked mine but quite a few switchblocks do earth through the bars via one of the mounting screws

Not checked mine but quite a few switchblocks do earth through the bars via one of the mounting screws

....interesting ..... anyone confirm this on the TRX?

IIRC someone once posted the wiring diagram ... in fact I think I have a copy somewhere ... I'll have a look in the morning

I hope this helps ... if it's not clear enough on here I'll email a copy to you

DEFINATELY a bad earth Dave. Could be pretty much anywhere in all honesty but try all earthing points to the frame, battery negative cable too.
Cal`s advice is good advice.

Cheers Mince
Dave; A couple of questions/answers, does the starter motor turn over ok? If so likely the battery earth is ok as with the starter motor earth, which leaves the main earth for the wiring loom, Dont know where it is located on the bike but if I get a chance I will have a look later.
It might not be the actual connection but the wire itself being coroded or broken

Starter motor is fine and battery is healthy.

I'll have the tank off and check the earth points I know of and check for any I dont.

Thanks for the help.

It is definately a poor earth!

OK so spent some more time in the garage looking at this one.

The story so far is:

1. Rear light was playing up: working on side lights but not on full lights. Brake light wasnt working either from the front brake lever.

2. Replaced the brake light switch under the front brake lever and that sorted the brake light.

3. Took the Left Hand switchgear bolts out to take it off the bars to have a look at the light sidelight/mainlight switch.

Now I've got sidelights working ok but on mainbeam I have indicators 'glowing' and when the indicators are on, the headlight 'glows' and flashes too.

This happens whether the switchgear is bolted on to the handlebars or not.

I've not fiddled with anything else at all so I cant see how an earth connector somewhere else like under the tank or arond the battery can be loose from me taking off the rear light and the LHS switches......??

Any one any more clues for me? Re-mot is Thursday morning first thing!

have you got the rear light fixed?
do you have a multimeter? if you do check for continuity with a low ohm setting on all the earth terminals in the lighting circuits, you are looking for a good path to earth for all circuits, also check the bulbs are the right ones.
it wont be the battery going flat, it is definately earth related somewhere in the loom.
if you dont have a meter you could try the switches again but disconnect parts of the loom from the plugs under the tank, one at a time, it might point you in the right direction to where the fault lies

The brake light issue i sorted by replacing the switch under the front brake lever.
But the LHS switchgear had an issue whereby sidelights worked but main lights only connected sometimes. All i did was take off the LHS switchgear by undoing the two bolts and splitting it into two as its designed to do
I cleaned and 'roughed up' slightly the connectors for the side/main light slider switch which cured the dodgy connection issue I had with the main lights only connecting sometimes.
But then the current problems started.
It must be something in the LHS switchgear, but all i did was split it and take it off.
Have tried putting it all back to how it was.
Does anyone know if there is an earth in the switchgear to the bars, or can decifer the wiring diagram above?

can't borrow a LH switchblock to isolate that being the problem and if so use it for the day to do your MOT the &^ck it is you guys get stung with each year.