Suzuki A100 electrical problems

[gazray4699]

Hello,

I'm a fairly new rider, having passed my CBT only a month ago and I've been riding a Suzuki A100 motorcycle for that time. I think it's about a '79 model. Could be wrong though.

Anyway, my issue is this. We bought the bike several years ago and restored it to drivable condition, it also passed it's MOT. It wasn't used for several months however until I came into possession of it, bearing in mind the new battery was sitting around for a month as well in a damp, cold garage.

Now after riding it for some time, I've come to notice that the electrics are a little... erratic. It's common for the lights on the dash to become dim and whenever other lights are used, they dim even further. My indicators also have a tendency to work but not flash, just become solid colour until I turn them off. At other times, the indicators even fail to display completely, usually when my battery has died. Now... I don't stall very often now but no improvement is clear and I'm wondering what the cause could be. Current opinion is that it is either the battery not charging correctly or the alternator. The alternator was tested however and was proven to produce a charge, probably not the amount it should. Even so, sometimes when the bike is started, the electrics may suddenly be perfectly fine once again. It's a confusion situation, especially for someone who knows hardly anything about motorcycles. Can anyone possibly shed some light on this?

Thanks in advance.

[finpos]

If the charging system is ok, then obvious candidate is the battery is not holding charge, no matter how new it is. Some of the small cheap ones don't seem to last any time at all. Also possible with a bike of that age to be any number of poor connections / earth points in the wiring loom.

f.

[gazray4699]

You see, that's what I thought... but so many people have said that because the alternator isn't producing six volts (the size of the battery) when the bike idles, then it's the alternator... it does charge but doesn't tend to reach much as far as I'm aware.

As for the wiring, I'm pretty sure most of it was replaced and reconnected during the restoration.

Edit: The alternator theory might not be true though as the bike can run for three days before the electrics begin to fail altogether. Surely I'm not draining that much that it would run out so soon, even with a lazy alternator, right?

[finpos]

Does sound like it's not charging correctly when you put it like that..

f.

[Pete.]

To test the alternator, charge the battery, run the engine, put a volt meter across the battery and turn on the lights. If it gets below 6v with the lights on or off it's not charging properly.

I had one of these as a first roadbike back in '87. Don't remember it having any charging problems though. As for the alternator I would expect it to either work or not work, it's a pretty basic system.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Vincent]

Do the lights get brighter and/or the indicators flash when you rev the engine up?

[cb1rocket]

I have a '79 GP100 and the electrics are similar I assume. The lighting circuit is direct, so if the lights work when the engine is running the the alternator would be fine. The battery are practically useless (mine is already playing up!).

Other thing is to check the rectifier is working ok as these can go at times and the wiring being naff (mine is).

Check the alternator output leads on AC on the multimeter and see if they go at least above 20v when the engine is rev'ed.

Battery output leads, should read between 6-8v DC and again when rev'ed.

[gazray4699]

I will check the alternator leads and battery leads when I have a free moment and am able to borrow the voltmeter again.

The lights do get brighter and occasionally the indicators flash when I rev, though when the charge level is fairly low, they simply get brighter but don't flash.

Anyway, I'll test out what is suggested and let you know the results when I can. I'd really love to have this fixed as using the bike for commuting, indicators are fairly important.

[Agentspiller]

I have a simular problem with my 1989 GP100, the indicators won't work generally, but if I leave it switched to the right then randomly they will begin to flash quite quickly, if I move tue switch to centre or left then back, nothing..... Been told to go round and check the earth contacts on every indicator and ordered a new rectorfier but running out of ideas already? Help!!!!!

[cb1rocket]

[Agentspiller]

My electrics are really quite random some time i have fast flashing indecators high speed they are solid, some times the horn just blips and other times works, went for a long ride today now i haveno power at all not even a neutral light. Is this a new batt and flash unit???