Electrical issues

[Hywel]

At tickover all my lights (clocks, neutral light, head/tail lights and indicators) pulse... getting brighter and dimmer. The indicator has a habit of flashing quite incosistently / too quickly when the revs are low too and it evens out when I up the revs a bit but even at high speed I notice the headlamps all of a sudden getting brighter then darker and I sometimes notice the indicators going a bit mad.

I know it doesn't sound like much but it's quite distracting and takes my attention off the road a little. Anyone else experienced this?

Reckon a new battery is the answer? It doesn't sound very strong when I push the starter and it usually takes a while to fire up the bike.

It's a '98 Honda CB600F by the way.

[rennie]

as it's a honda it's probably the reg/rec on the way out!

[Hywel]

Hmm... is there a way I can reliably check that this is the problem?

[rennie]

yes if you've got a voltmeter.

measure the voltage across the battery engine off, should be about 12v.

start engine

measure voltage across battery again should have gone up to about 13 ish.

rev bike, volts should maybe go up a bit more.

if volts are going up too much reg/rec is gone and this will fry battery.

do the above and post results if still struggling.

[Hywel]

Just gave this a go.

My Voltmeter read 12.4v across the battery when the bike was off, switched the bike on and at tickover it was reading between 12.3v and 12.5v, so around the same. I picked up the revs to about 3000rpm and saw an increase in voltage to around 13.2 - 13.4v, when I pushed the revs higher; up to around 7 - 8krpm it dropped back down a little to 12.8 - 13v but saw no major fluctuations, so revving the bike hard didn't push the voltage up much. Does this mean the reg/rec should be ok?

Can the erratic indicators at higher revs, and inconsistent head/tail-light intensity be caused by an old battery due for replacement? I flipping hope so

[Guest]

The info you have posted , does suggest the reg/rect is currently performing ok...

Any idea how old the battery is? Cos thats what I'd be looking at next...

[Hywel]

The info you have posted , does suggest the reg/rect is currently performing ok...

Any idea how old the battery is? Cos thats what I'd be looking at next...

 

Well, It's the one that was in the bike when I bought it in December, and it had been sat in the dealer without anyone touching it for months... when the bloke tried to start it for me it took some doing, and when the bike is cold the turnover starts slowing down after the the 3rd or 4th try if it doesn't spark before then and generally it feels pretty weak unless it's warm and I've just been riding hard for a while, in which case it starts fine.

What about the madness with my lights though? Would a weak / old battery do that?

I'm guessing it's worth buying one to try it at least.

[j4ff]

sounds like the battery wont hold a strong charge.

The indicator thing is a lack of power to the relay/flasher unit

[Guest]

Its 12 years old ... this could throw all sorts of electrical gremlins in the mix ...

You've checked the reg, this suggests it charging correctly. Jeff is on the money, it could be the battery is just tired and isn't holding a charge. Is the easiest option to stick a new one in. Around the £40 mark for a new un.

If you wanna do some digging before hand. Unplug all the indies and check the connections, also the plugs to the headlights. If these have water ingress and have corroded any, it will cause the symptons you describe as well. The fact it is all the lights and indies though, does point to the battery.

If the connections are bad, they'll need a clean with emery cloth or needle file etc to renew the contacts .. and then apply some electrical grease (its name evades me .... sure WF will chip in when he pops in)

Like I say, easy way is stick a battery in and see what happens At least you'll know thats new, if nothing else!!

[TC]

Just gave this a go.

My Voltmeter read 12.4v across the battery when the bike was off, switched the bike on and at tickover it was reading between 12.3v and 12.5v, so around the same. I picked up the revs to about 3000rpm and saw an increase in voltage to around 13.2 - 13.4v, when I pushed the revs higher; up to around 7 - 8krpm it dropped back down a little to 12.8 - 13v but saw no major fluctuations, so revving the bike hard didn't push the voltage up much. Does this mean the reg/rec should be ok?

Can the erratic indicators at higher revs, and inconsistent head/tail-light intensity be caused by an old battery due for replacement? I flipping hope so

 

Take the bike for a 20-30 spin (gets the recifier warm) and then check the readings.

Mine went down to about 8 volts when warm.

But all was normal when i did the test you did

[Guest]

Good point that. Forgot about em getting warm, apologies Hywel.

[Hywel]

Good point that. Forgot about em getting warm, apologies Hywel.

 

Dim problem! Just did a 45 minute journey in the baking sun, mostly quite fast roads and the latter part town speeds so I could've cooked an egg on any part of the bike. Left it running and took the side panel off with voltmeter in-hand.

Similar results really, except when I really give it the beans on the throttle it goes up a little higher than it does when cold, but still doesn't go past 13.9v at 8 - 10krpm.

Does that mean I'm fairly safe to rule out the reg/rect as a fault?

[TC]

Good point that. Forgot about em getting warm, apologies Hywel.

 

Dim problem! Just did a 45 minute journey in the baking sun, mostly quite fast roads and the latter part town speeds so I could've cooked an egg on any part of the bike. Left it running and took the side panel off with voltmeter in-hand.

Similar results really, except when I really give it the beans on the throttle it goes up a little higher than it does when cold, but still doesn't go past 13.9v at 8 - 10krpm.

Does that mean I'm fairly safe to rule out the reg/rect as a fault?

If you got the same results I would say its fairly safe to rule it out.

Like i said mine went down to about 8volts when warm.

[rennie]

sounds like reg/rec is ok to me!

I'd buy a new battery and see what happens then.

[eastanglianbiker]

agree that its all pointing at the battery being on its way out

[Guest]

Sure looks that way.

[Hywel]

Yey!!! Plopped a new battery in just before leaving for work and the bike burst into life on the first dab on the starter button, light intesity is solid and the indicators all flash at a consistent rate, whatever the revs.

Thanks for your help everyone!

Now I just want to source a standard Hornet headlamp plus wiring and mounting brackets, these twin lamps aren't the best and have been wired up with household wiring which is all a bit dangly between the forks.

[Guest]

Can't belive I missed this!

Glad it you got it sorted

I take it, judging by the absence of posts, that it is STILL sorted?