Indicator problem HELP

[Trigger]

This is on a SOHC but, its a CD250. When at high revs the indicator flashes that fast that it stays on, it will go back to the right flashing speed, if you hit the brake or at under 50mph. Had this problem for a while now, and had a ton of electric guru's had a look as, I am shite at electrics.
Things already checked and changed:
1) Changed the relay three different units (no different)
2) Checked the output from the alternator (is perfect and has not lost any fluid from the battery)
3) Checked the rectifier output (is perfect)
4) Changed the indicator bulbs from 21w to 23w (still the same problem)
5) Has not blown any fuses or bulbs
6) All wiring in very good condition

Anyone come across this problem before?

[hairygit]

No, but if you change to an aftrmarket flasher unit made to run led bulbs, they are electronic, and have the ability to run a total load of 0-250w at 90 flashes per minute, the law requiring 60-120, so bang in the middle. I've had one on my chicken chaser for about 10 months and no problems at all. I was so impressed I bought a few more just in case!:-D

[AshimotoK0]

Don't know that bike Graham but  from what I can see on a brief look on the Net. I  gather that  it's a two wire flasher on that model. What's the method of regulation on that bike to prevent overcharging the battery at high revs.? The early twins had a Hitachi unit which incorporated a voltage detector and thyristor 'crowbar' to prevent overcharging (mounted under the battery box) ... bit like the action of zener diode on old 60's Triumphs but a lot more precise. There must be some method of prevention of battery overcharge on that bike and if it's malfunctioning and the flasher has any kind of electronics in it, then the overcurrent charging pulses could cause an  erratic flash rate.

This is all supposition as I don't know that model. Do you have a circuit diagram? Is it a CD250U. If it was a CD250 'Dream' from '68, I'd be hightailing it down the M1,  flashing the cash at  you to part with it 

Ash

[AshimotoK0]

Don't know that bike Graham but  from what I can see on a brief look on the Net. I  gather that  it's a two wire flasher on that model. What's the method of regulation on that bike to prevent overcharging the battery at high revs.? The early twins had a Hitachi unit which incorporated a voltage detector and thyristor 'crowbar' to prevent overcharging (mounted under the battery box) ... bit like the action of zener diode on old 60's Triumphs but a lot more precise. There must be some method of prevention of battery overcharge on that bike and if it's malfunctioning and the flasher has any kind of electronics in it, then the overcurrent charging pulses could cause an  erratic flash rate.

This is all supposition as I don't know that model. Do you have a circuit diagram? Is it a CD250U. If it was a CD250 'Dream' from '68, I'd be hightailing it down the M1,  flashing the cash at  you to part with it 

Ash

If it did turn out to be a three wire, separate regulator,  the third (ground) wire would need a good connection to earth, in order  to perform regulation  properly. Plus if it was also a 3-wire flasher, that too would need a decent earth to it's 3rd  GREEN wire.

[Lobo]

I'm with Ash here Trig, it would seem the electrics are over-volting; the battery would not necessarily boil etc if not run @ this condition for extended periods etc.

Understand you hate electrics, but from the pic below, you can see that if the regulator earth wire is disconnected / broken etc then the breaker switch will stay in the upper position, supplying the Field Coil a voltage proportional to the engine RPM. And since the field coil is at a higher & higher voltage iaw RPM, the alternator windings get more & more excited (ooh) - a viscous circle.

One other thought, & I'm way outta my depth... Ash, Bryan... the older bikes had windings switched in according to load... eg the headlamp on. IF the elects had been modded to have all windings perm switched in I guess this would give what Trigger's seeing?

Simon

[Bryanj]

One of two possibilities come to mind.

(1) check the voltage at the battery when the indicators are going crazy as per others advise

(2) check the relay mounting as vibration can drive them nuts

[Chris400F]

the older bikes had windings switched in according to load... eg the headlamp on.

I remember having this problem on a CB125, dirty contacts meant windings not switched in. Not good at night, headlamp on = engine stop ....

My thoughts also that overvoltage is the problem. Braking would give extra electrical load (brake light) so reduce voltage.

The only wiring diagram I have found (CD250U) shows regulator/rectifier as a single unit, no obvious switching of windings. Agree to check wiring and connections otherwise I would suspect the unit itself.

[AshimotoK0]

Is this the model Graham?. If so I would suspect the regulator/rectifier possibly, as mentioned by others.

Ash


[ Guests cannot view attachments ]

[Trigger]

Yes Ash, that is the baby

1) Relay is WRE04 12v 18/23w with 2 pin rubber mounted
2) Battery reading 12.84V at stand still
3) Battery reading 14.10V at tick over
4) Battery reading 14.36V at full revs
5) All earth points good

Voltage from battery with indicators going crazy (full revs) is 14.18V

[Trigger]

OK, have just been through the whole system and can't find anything.
Alternator not going to ground ect,ect. Will try Hairy's LED suggestion and see what happens.

[mike the bike]

Aye Trig, check the battery voltage.  It sounds like it's going too high, probably thanks to a dodgy regulator.

[Chris400F]

it will go back to the right flashing speed, if you hit the brake or at under 50mph

What happens to the battery voltage if you apply the brake (or turn the lights on, to add an electrical load) at high revs with indicators going crazy?
Is there something a bit marginal here that causes the indicator relay to throw a wobbly.
Sounds strange if same symptoms with three different relays but something else to try.

[AshimotoK0]

That's a real sh*tty circuit diagram I put on here Graham and can't quite work out the colours but looks like 3 yellows out of the alternator so 3-phase but I can't see a field coil but could be a PM rotor (there is a 4th coil but it looks like the power  generator for the CDI). Really out of touch with models  after 1977, sorry    . If it is PM (permanent magnet)  and 3-phase, why not try temporarily grafting in a 400/4, CB500/550 or 750 rectifier and link directly to the battery, making sure the battery is pretty flat before testing it. The battery will act as it's own regulator until it becomes charged. also have you tried another battery ... just in case !

Cheers ... Ash

[Trigger]

Up date:
1) Changed the rectifier and it is the same
2) New battery (same as before)
3) The reading at the battery is 12.48V with full beam on, brake light on and indicators on. Indicator still going nuts at full revs.
4) Have not tried Hairys LED suggestion yet.
5) Had 4 electric bod's in the trade look at this problem in the six weeks and everyone is scratching his/her head.

[royhall]

I'm looking forward to knowing what this problem is. But probably not as much as you are Graham.