'97 XJ 600 Intermittent charging

[Dimonn]

Hey guys, I have an interesting problem.

I have 1997 XJ 600 that i bought last year after having two previous bikes stolen outside the drive. Because I didn't want the same happening to this one I decided to install an alarm/ immobiliser. The alarm i installed is the sky 5000 but when it came to setting up remote start i connected one of the wires wrong and cause the battery to drain fully (I literally had no ingnition). The wire i installed incorrectly is the blue wire going into the blue/white starter cut off relay, so i just took it out and reconnected all the circuitry without having the remote start feature.

Ever since then i have been having charging problems, particularly when the lights are on. After playing around with the multi meter i have realised that if the bike is in neutral or the clutch is pulled in the battery is charging (I also noticed the lights get slightly brighter) so i started testing components and so far i dont think its my starter cut off relay and not my main relay assembly. I did think that it is the rectifier but when it is in neutral the voltage stays a constant 14.2V and I was under the impression that they either work normally or the go completely. I also checked the coils and the impedance is within the specifications so my though at the moment is that something is back feeding into one of the earths when the neutral switch is not active. I though of the neutral switch diode but im not sure whether it can do something like that.

The voltage across the battery when the clutch is pulled in or it is in neutral is around 14.2V without lights on and 13.9V with lights on, the voltage when in gear and the clutch lever is slightly pulled out (way before biting point) drops to 12.7V without lights and 12.3ish with lights.

Any idea whats causing it to do this, I am completely stumped.

[J.M.]

Are you absolutely sure that it is intermittently charging?

How old is the battery? Could the battery not be on its last legs and not holding a charge very well. That combined with the draw that the alarm will inevitably draw could lead you to experience flat battery symptoms when in reality there is nothing wrong with your charging system.

Anything above 12.4v should be adequate for charging a bike and ensuring that the battery does not flatten - providing that the battery is in good health.
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2004 R1 & 2018 XSR900

[Dimonn]

The battery was the first to be changed (Yuasa). Im not sure whether its charging or not when the bike is not in neutral and clutch disentgaged, all i know is that if i ride it for more than an hour and a half at night there wont be enough charge to stat it up again so i have to leave it in neutral after i arrive for a good 10 minutes to charge the battery back up.

I though about the alarm and unplugged it completely for two weeks and see if it has improved, no change whatsoever.

The voltage across the battery literally drops over 2V as soon as i move the clutch lever slightly out (way before it bites but enough to tell the bike im in gear)

Ive never encountered this before and the only explanation i have is that current is back feeding through a faulty component but i cant think which one or how to test for it.

[Walloper]

The battery is recharged by the alternator at a certain engine RPM.
It normally doesn't charge much at idle and should begin charging at about 2000rpm.
The charging system is conrtolled by two things. A rectifier and a regulator.
The rectifier allows only + current produced by the alternator to flow to the battery. The - current is blocked and ignored.
Alternators are called alternators because the produce + and - current. So the current 'alternates' between + and -.
A generator will keep pumping out current at higher and higher levels until it reaches it's highest RPM or melts/explodes.
To be able to use the current produced at all RPMs a regulator is installed. This works like a relief valve and limits how much power goes to the system to charge. (A bit more complex than that).

If the alternator is not charging at your cruising speed then it may be that the regulator is not working properly and limiting the charge when the engine is 'off idle'.

Check the battery with the engine at idle and when the engine is lifted off idle. If the charge drops then it is the regulator.

A more worser thing could be the alternator is broken and so only make current at lower speeds. But I would check the regulator first.

There will be a forum electrician along soon I hope.
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W-ireless A-rtificial L-ifeform L-imited to O-bservation P-eacekeeping and E-fficient R-epair

[DMCpro]

Hi mate do you have a good multi meter? If yes then set it to amps ( and change the prongs to fused amp circuit) remove the positive lead and connect it to the + prong on multi meter connect the - prong to the battery itself. What does it show with the ignition switched off? If it's below 0.05 then you are ok anything above this then there is a drain on the battery and it will go flat
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Honda CB-1, TS125X
VW Golf Estate

[jjdugen]

Yes, a strange one for sure. Easiest first check, just take the clutch switch off the lever unit and tape it out of the way. If you are back to charging properly, then I would hazard at a short somewhere in the clutch switch to ECU wiring.
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[Dimonn]

@Walloper when the bike idles cold (1200RPM) the voltage is around 13V. Once the revs increase to above 2000-2500 the voltage rises to 13.8 sharply and carries on rising until it hits 14.2V and doesnt go over that and the voltage is constant so no fluctuations.

@DMCpro Ill try that once i finish uni for today

@jjdugen I suspect a short, do you mean remove the switch so the bikes still thinks the clutch is engaged even though it is not?

[Walloper]

[jjdugen]

Hi, yes, forgot to say tape up the switch so the operating plunger is pushed in, as it would be with the clutch lever fully out.
As this is the voltage line causing the problem, this would be my first thing to check.
Actually, (having another think), this switch carries twelve volts from the main loom, and, when 'made' as in the clutch out, it should be sending the twelve volts down the other lead to the ECU. Must be another interlock connected to this circuit, probably the neutral switch. I'll see if I can dig out a diagram for it and have a look.
____________________
The CBR900RR has been sold. Aprilia Falco worms its way into my heart.
Try Soi 23 on Amazon for a good read.... Self promotion? Moi?

[Dimonn]

@Walloper you say its simple but i have been scratching my head at it for a month

I got delayed from university so its too dark to do anything today but i uploaded a video showing the lights dimming as i move the clutch lever out a little bit, sorry its dark but that's the only way you can see it: https://www.youtube.com/watch?v=Lv4QDw8J92k

Ill tape up the clutch switch tomorrow morning thanks for your help guys i actually never though of that

[Dimonn]

Here is the wiring diagram for the 97 onwards model from the haynes manual: https://i1028.photobucket.com/albums/y348/Dimon92/wiring_zps8e4295c1.png

[Walloper]

[Dimonn]

The real difficulty is that a lot of the stuff is not easy to identify or access.
[/quote]

You can say that again, i swear the wiring on an XJ is a lot tighter than on my old YBR where all the wires had enough slack to play with. Also a huge connector block is under the fuel tank

Also I removed the clutch switch and there isnt any voltage drop now so there is something shorting along that line, maybe a component that burned out when i miswired it, ill keep looking but does anyone have a good method how to test different components with a multimeter and tell which one it is?

For now ill just ride it with the clutch switch out until i solve the problem, again thank you, i actually never thought of doing that