Rear light pulses with indicators
 

Hi guys, I noticed the other day that the 2004 XTX rear light pulses when the indicators are on. It happens when the running light is on, and also when the brakes are applied (it 'pulses' brighter of course when brakes are applied).

This happens when either left indicator, right indicator, or hazards are on.

The indicators are standard, the rear light bulb is an led one. I get a feeling that there is a short somewhere?

Here is what I have done to see what is going on:

-Remove rear bulb, measure voltage of the 'tabs' in the light socket, sure enough when indicators are on the voltage goes up and down, when indicators are off it is constant.

-Unplug rear light wiring (gear selector side of bike, underneath where pillion handles would be) and measure the voltage coming out of the wiring loom towards the rear light. There were the same fluctuations in voltage when indicators selected, but constant voltage when not selected.

-Unplugged indicators from wiring loom on gear selector side of bike under pillion handles and measured the voltage at the same places as described above, same result. (This leads me to think that indictor bulbs are not to fault, and there is a short somewhere deeper in the system)

-Unplugged rear brake foot pedal switch above airbox on brake pedal side of bike. The rear light still pulses when indicators are on.

-Unplugged indicator relay, this stops the rear light from flashing when the indicators are selected (obviously), and so I believe there is a short somewhere inbetween the relay and the indicator bulbs. When the indicators are selected the wires going into the relay give a constant voltage, when the indicators are not selected there is 0V, as expected.



I have tried to follow the wires around the wiring loom but I can't see where they go.

I am very grateful for any help,

Thanks

Harry


p.s. I just had a thought, it's not a safety sytem that has been included so you are more visible when indicating is it?

Sounds like a bad earthing

Sure sounds like a bad earth.

Run a temporary loose wire from the battery earth to the earth wire on the tail light, then test to see if that fixes it.

If that does not fix it, run the loose earth wire to each indicator earth wire one at a time & retest.

EDIT:

Ok I just ran an earth wire direct from the battery to the tail light earth, had the same problem. Then ran it to rear indicators one at a time, same problem. The wire I used was not long enough to reach the front indicators, I will try that another time.

Another thing to add: if I leave for example one of the indicator wires on the rear left indicator unplugged, the front left indicator flashes at a faster rate as expected. The rear light also flashes at this same faster rate. This further points to a bad earth I think.

Any other ideas?

Many thanks

Harry

If you have a volt meter, can you put it on the Milli volt setting, put the positive cable on the battery earth & the neg cable on the tail light earth then make it fault & give me the reading, also do the indicators circuit.

After taking the readings can you remove & sand the earth wire at the battery, also remove the earth strap at the engine & sand paper the wire & earth point on the motor & put it back together.

Can you also give me your battery voltage with the bike running with the revs up around 3000rpm mark.

Arghhhh this morning the indicators or running light won't come on! The brake light comes on when applied though. I get a feeling a fuse has gone somewhere? Where would this mysterious fuse be?

Also now the lights aren't coming on, when I measure the voltage of the two wires going into the flasher relay, it is always 0V, so a fuse has gone somewhere inbetween the indicator switch on the handle bar and the relay?

Thanks

Harry

Just found the signal 10A fuse, it's fine!?! I swapped it with a spare one but it didn't change anything.


EDIT:

I checked all the other fuses, they were all fine. Then I saw a seperate fuse outside in a white box called 'park 10A', and yes that fuse had blown.

I swapped this with a spare, and now I have the lights and indicators back. I probably shorted it out when trying to measure the voltage of the rear light wires in the connector, I reckon the volt meter probe slipped a bit when I leant up to push the indicator button, shorting the park light.

So, I am back where I was. The fact that when the parking light fuse blew the indicators stopped working surley shows that these two circuits are joined in some way (bad earth) when they are not supposed to be?

Battery V at idle (1400-1500) is 14.30V

Battery V at 3000 is 14.33V


I have just realised something, the pulsing problem I have only seen when the engine is off as I can't see the light when on the bike obviously. I just tried it with the engine running, and at idle you could see it pulsing a little bit, (although it is so little it could just be my eyes playing tricks, I have been looking at flashing indicator lights for ages lol), and then with some revs you can't see it pulsing, the light gets a bit brighter anyway.

I don't understand why this is the case that it pulses when engine off but not when running?

Try leaving your battery on charge over night and see what happens.

Just checked my XTX, with the key on motor not running, with the indicator flashing my tail light flashes bright then dim very slightly in time with the indicator. It does not do it when the bike is running.

So yours might be normal, what is the battery voltage with the key on & the indicators flashing??