Is my battery dead?
Discussion
In many ways it's fairly straightforward now. It's not an intermittent fault ((they're the worst), you've got a brand new fully charged battery and you're studying electrics. All you have to do is 'follow the power' with a tester and work out which component is doing what it should or whether there's a break / short in the loom.
Not that straightforward means quick - you just need patience and daylight.
Not that straightforward means quick - you just need patience and daylight.
Take a step back from electrical faults.
Check kickstart sensor, kill switch and gear sensor again. Then try start,If it click, dims the lights but won't turn you need to look at the starter.
You alao need to check earths and immobilisers if yiu have one but my money is on the starter or a switch!
Check kickstart sensor, kill switch and gear sensor again. Then try start,If it click, dims the lights but won't turn you need to look at the starter.
You alao need to check earths and immobilisers if yiu have one but my money is on the starter or a switch!
Edited by Prof Prolapse on Friday 2nd October 08:19
Benbay001 said:
Steve Bass said:
What's the voltage pulling down to when you thumb the starter?? You need to see what the voltage is when you're trying to crank.
I cant imagine there is any voltage change now because there is litterally no power going to anything with the key in the on position. 
You need to understand whats happening. If there's no change when you thumb the starter, then no current is being drawn. Then start tracing the current path to see where the issue is.
Guess nothing. 1St rule of Electrical engineering!
So start at the Battery and follow it through to system. There's probably a master relay that switches from a signal wire via the ignition key so switch power to the main circuits.
But you're giving conflicting information. You stated that when you shorted the battery terminals, there were no sparks. Hence the indication of a dead battery.Yet now there's 12.7 vdc which would cause sparks if shorted. Which is it??
He said he has a new battery Steve. He also said the lights go dim when you try and start, which is why I suggested now looking at the starter, and away from the wiring for the moment (except in relation to the starter of course!).
Especially with it being an old Jap bike, which anecdotally I've heard the starters don't last.
Especially with it being an old Jap bike, which anecdotally I've heard the starters don't last.
Edited by Prof Prolapse on Friday 2nd October 10:42
If it's killed a new battery already I'd almost certainly expect the reg/rec to be duff. Come and see me if you want one as I've got one that'll fit straight in you can have for not much money, while you're doing it you may as well try and work out how to get it more air/more cooling in the way of heatsink plates or similar.
MotorsportTom said:
If it's killed a new battery already I'd almost certainly expect the reg/rec to be duff. Come and see me if you want one as I've got one that'll fit straight in you can have for not much money, while you're doing it you may as well try and work out how to get it more air/more cooling in the way of heatsink plates or similar.
Cheers.Battery is on charge atm. Ill start the bike tomorrow and see what voltage reading i get when its running.
Looks like ill probably be needing that reg/rec if you dont mind?
Benbay001 said:
MotorsportTom said:
If it's killed a new battery already I'd almost certainly expect the reg/rec to be duff. Come and see me if you want one as I've got one that'll fit straight in you can have for not much money, while you're doing it you may as well try and work out how to get it more air/more cooling in the way of heatsink plates or similar.
Cheers.Battery is on charge atm. Ill start the bike tomorrow and see what voltage reading i get when its running.
Looks like ill probably be needing that reg/rec if you dont mind?
No doubt I'll need it fairly soon after you fit it but I'm sure I can swindle another through work
Lemme know when you want it etc and I'm sure we can sort something out bud
Benbay001 said:
So, just tested it.
Battery was showing 13v with no load.
With starter going 10v
idle 14v to 16v (
right?)
When i rev it volts drop to 6 to 9.
Almost definately reg/rec, right? And not alternator?
Starter relay performed marvolously, so the two issues are probably related.
It shouldn't be dropping when you rev it so almost certainly reg/rec! Battery was showing 13v with no load.
With starter going 10v
idle 14v to 16v (
right?)When i rev it volts drop to 6 to 9.
Almost definately reg/rec, right? And not alternator?
Starter relay performed marvolously, so the two issues are probably related.
If you can stop riding it and check the plug etc as it can get hot and go brittle as well as making the wires hard and brittle and it turns into one big ballache.
Take a picture and send me the plug pattern to make sure my one will fit too, it's the same for the VFR750 and Blade so I imagine they kept it similar.
Just for your sanity, check the generator coils before you commit to the reg/rec.
Set the volt meter reading to AC voltage and measure from each of the yellow generator wires and ground. Voltage might be around 70vac but make sure you're not getting a coil braking down. Test exactly as you have, at idle and will a few thousand revs to be 100%
If the 3 wires all read the same and are stable 2ith only voltage rising with rpm then you know it's the rectifier unit
Set the volt meter reading to AC voltage and measure from each of the yellow generator wires and ground. Voltage might be around 70vac but make sure you're not getting a coil braking down. Test exactly as you have, at idle and will a few thousand revs to be 100%
If the 3 wires all read the same and are stable 2ith only voltage rising with rpm then you know it's the rectifier unit
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