Wierd electrical issue.

[g-wali]

1991 Sportster 883 Deluxe

Here is the issue. Randomly while riding all of my lights turn on.  Sometime brightly but, mostly very dim and shaky like there is small part of a wire barely touching.  If it was just one light it would be easier for me to find but, all of my lights.  Brights, Turn signals front and rear are all on.  Then it will just stop.  It doesn't get brighter if I rev the engine and doesn't really matter if I turn off the power and turn it back on while riding.  Anyone have any suggestions on how to trace something like this down?  It doesn't happen all the time but, it has been happening more often which makes me think the wire that is touching is slowly burning off more of its insulation.

[messed up]

lost headlight on my softail once. wires broke inside insulation coming out of shrink wrap. Hard part is they would touch and work and it turned out to be both hot and ground.

[Panzer]

Have you checked cable connections on the battery and connections going to engine and chassis grounds?
Corrosion at bat. terminals?
These are good places to start.
If in doubt, remove the cables, shine them up and replace.
How about looking at the main harness connection under the seat for being tight......vibration does funny things.
Let us know.

[andyxlh]

Hmm without a circuit diagram at hand it is kinda hard to guess, but the guys above have had a good go.
What I'd do is check in 4 places:

1. the battery terminals - make sure they are good and clean and tight. Shoildn't cause this problem but there u go and whilst you are there make sure the earth strap is not frayed or broken where it attaches to the frame.
2. take off the seat and check the circuit breaker plate - there are 4 circuit breakers, the one with the thick red wire going to it is the main feed (30A), the ignition white is i believe the feed for the headlight (comes in from the switch) - look for some way in which the wiring from the ign is being shorted across the terminals of the circuit breakers. also check down near the oil tank where the wires can rub against it and the frame.
3. remove the headlight and look in there - there's a whole lot of wires shoehorned in that space. check for rubbed wires - look inside the casing for shiny metal where thay have been rubbing. Also open the white connectors and have a look inside them for corrosion or other stuff
4. check the switch - mine is a 3-way which i have replaced twice over the years. Also bend down and look up under the mount where the wires come out of the back of the switch - check for rubbing.

The electrics could well be using the lights as an earth route - because the correct earth point is shot so the electricity is taking the path of least resistance thro' the circuit which happens to be the lights. There is an earth under the handlebars too for the switches on the grips - it attaches behind the eyebrow.
The best way would be to have a good wiggle of these points with the bike running and the lights flickering. that way you might be lucky enough to see it going on and off as the wiring is moved.

best of luck
Andy
Sydney

[Evo160K]

Like andyxlh suggested, check at the keyswitch.  With the engine running, I would push and pull all of the wires at the keyswitch and feel for hot spots under the insulation.

[g-wali]

Alright so more testing and I replaced the turn signal canceller module.  After trying to find out what was happening I realized that only my turn signals were actually having the issue.  So Now They don't turn on randomly but, they do turn off prematurely.  I have cleaned the battery terminals and the cables do not appear corroded. 

This only is an issue when my bike is warmed up and have been driving for about an hour. 
Only when I am using the throttle
The turn signals go to turn on and then shut off

If I am sitting at a light and I have the turn signal on it works properly. 
The second I blip the throttle the turn signals shut off.

Not sure what to check next.  I am waiting on new breakers.  They test fine when I have the seat off and not riding.

Also,  this started happening today on my way home.  I could reproduce it and I was awesome. Turned off the bike ran in the house opened the garage.  Started the bike back up. Rode in to the garage and then everything and couldn't reproduce it.  So I think that something is heating up and then not working properly.  Any suggestions what this could be.  My charging system is working properly and tests properly.  No grounded loops that I can find with my Ohm meter.

[andyxlh]

Hmm - the australian '91 didn't have a turn signal canceller - it had switches that stayed in until they were pushed out to hold the turn signals on, and a car-style flasher pot in the headlight I believe. I think the first bikes with the turn signal canceller were '94 models with the electronic speedo, to allow the turn signal module to have an input for speed and distance and know where to turn off.
The circuit breakers are cheap and left me stranded on my bike last year - so replacing them is a good idea. This is often a heat related issue as they get hot with the current runnign through them then they are dirty inside - increased resistance - and then they cut the line. Not sure how this could cause your problem tho'.

[14Frisco]

I think the first bikes with the turn signal canceller were '94 models with the electronic speedo, to allow the turn signal module to have an input for speed and distance and know where to turn off.

I don't know about the Australian models, but the turn signal canceller was introduced before electronic speedos.  Pulses were generated in a hall effect sensor in the mechanical speedo, "driven" by the speedo cable, and sent to the turn signal canceller module.

[andyxlh]

cool. I'm probably wrong there, My bike has the indicator switch that stays pressed in until released - not spring loaded - I thought they went through to '93 here but I'm probably not right. My mate's bike is a '94 with the first electronic speedo had the auto canceller system
cheers
A

[g-wali]

Mine definitely had a turn signal canceller.  I replaced it. So I am pretty sure it's there.  My new breakers should be here today so I hope to get those swapped out and find some time to ride some this weekend.