Idle picks up when headlight switches on

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PippiFyrecracker
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Idle picks up when headlight switches on

Post by PippiFyrecracker »

Rpm of idle increases and bike seems to run better when headlight is turned on decreases when turned off. Thoughts? I need to trouble shoot, blinkers stopped working too... Where to start?
sportston
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Re: Idle picks up when headlight switches on

Post by sportston »

Sounds like you have a poor connection somewhere. First thing I would do is start cleaning and replacing earth connectors. Check also any and all connector blocks for corrosion or breaking wires, especially inside the headlamp. It may take hours to clean or replace connectors, but if done properly it will eliminate many future electrical glitches. I replaced almost every single connector and terminal on my wiring loom to avoid problems like this. It took an age, but now all of my terminals are soldered and crimped with fresh metal. If you find an auto wiring shop online they can usually supply most of what you need to revitalise old looms, including proper japanese size bullet connectors and sleeves.
P.S. Don't underestimate the power of flux when soldering new terminals to old wire.
P.P.S. Remember, crimped terminals do not always make good contact on old blackened wire. If in doubt, solder it and cover in heat-shrink.
Good luck
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ConnerVT
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Re: Idle picks up when headlight switches on

Post by ConnerVT »

Or another perspective:

The T500 has 3 sets of generator coils. Assuming stock wiring, when the headlamp is switched off, only one set of coils are working. Switch the headlamp on, all 3 sets of coils are working. This was to limit the amount of current generated when the lights were off (low load), to help prevent overcharging the battery.

If your battery is marginal, there is a poor connection somewhere, or the headlamp switched off coil is weak, there may not be sufficient voltage for the bike to run properly. Turn on the headlamp, you now have 3 coils operating, and that may be supplying more current (even with the additional headlamp load) than the single 'lights off' coil is.

added: Start reading at page 84 - http://file.walagata.com/w/sundialmotos ... kiT500.pdf
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jabcb
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Re: Idle picks up when headlight switches on

Post by jabcb »

Blinkers likely stopped working because the voltage is too low.

As ConnerVT said, the T500 alternator has charging & lighting coils. If you are getting no output from the charging coil, then the only alternator output occurs when you turn the lights on. So the voltage might increase when you turn the lights on. With increased voltage, the bike then runs better.

You can verify that this is the problem by checking voltages.
To start investigating, charge up the battery. Then check the voltage:
1) with the bike off
2) with the lights off at ~2k rpm
3) with the lights on at ~2k rpm
4) again with the bike off
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sportston
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Re: Idle picks up when headlight switches on

Post by sportston »

ConnerVT wrote:Or another perspective:

The T500 has 3 sets of generator coils. Assuming stock wiring, when the headlamp is switched off, only one set of coils are working. Switch the headlamp on, all 3 sets of coils are working. This was to limit the amount of current generated when the lights were off (low load), to help prevent overcharging the battery.

If your battery is marginal, there is a poor connection somewhere, or the headlamp switched off coil is weak, there may not be sufficient voltage for the bike to run properly. Turn on the headlamp, you now have 3 coils operating, and that may be supplying more current (even with the additional headlamp load) than the single 'lights off' coil is.

added: Start reading at page 84 - http://file.walagata.com/w/sundialmotos ... kiT500.pdf
Aha. Now you see that is where a bit of model specific knowledge is very useful. I didn't know this about the T500. I would definitely suggest you check what Connor and Jab suggested first.
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PippiFyrecracker
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Re: Idle picks up when headlight switches on

Post by PippiFyrecracker »

update, ripped out the wiring, found some bad grounds, ordered power dynamo electronic ignition, rewiring everything from scratch. probably buying new battery as well...
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dorT500
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Re: Idle picks up when headlight switches on

Post by dorT500 »

PippiFyrecracker wrote:update, ripped out the wiring, found some bad grounds, ordered power dynamo electronic ignition, rewiring everything from scratch. probably buying new battery as well...
YIKES! :shock:
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Re: Idle picks up when headlight switches on

Post by sportston »

PippiFyrecracker wrote:update, ripped out the wiring, found some bad grounds, ordered power dynamo electronic ignition, rewiring everything from scratch. probably buying new battery as well...
Expensive way to go, but probably the best way to do it.
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PippiFyrecracker
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Re: Idle picks up when headlight switches on

Post by PippiFyrecracker »

tired of running into issues every other time i ride the bike, doing a rebuild...
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