Lights, capacitors, action.

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
Post Reply
The Vandal
Member
Posts: 79
Joined: Fri Sep 16, 2022 7:43 pm
Location: West Sussex UK

Re: Lights, capacitors, action.

Post by The Vandal »

Sorry to dredge this thread up again, I thought I had put my electrical woes behind me but it seems not.

I think I'd been lured into a false sense of success by the new battery but now that it has gone flat I'm realising there's still. No. Charging. Grrrr.

I'm getting voltage from the battery leads but no current (amps) with my meter in line with the battery.

Does that point to a dodgy connection somewhere?

I'm sure I got charge into the new battery at some point because the lights were dying at traffic lights at the start of a run but by the end they were staying on.

I feel like I may even have gotten some charge today because I'm sure I'd measured the battery voltage as having dropped way down to 2.5v the other day and after a 60mile run today it was up to 2.9v but obviously that's still very low and should (I would have thought) have been more after 60 miles of charging.
Groily
Member
Posts: 2151
Joined: Thu Jul 04, 2002 1:00 am
Location: NORMANDIE FRANCE

Re: Lights, capacitors, action.

Post by Groily »

What happened to the 7.5v you reported way back? I suppose they've gone awol?

Does ANYTHING light up if you turn anything at all on with the battery disconnected? If not, no output or wiring problem.

Your battery voltage readings = "Beyond Dead Flat". Seriously, it's Zilch Squared.
The 2.9 vs 2.5 may be just because the battery was warmer after 60 miles, or because the voltmeter isn't that sensitive.

You have to go back to basics here, and start again with the dynamo-only tests, then (if the dynamo is putting out volts still when tested with D and F joined etc etc) move up to the regulator and the A wire output test again. Then check the ammeter / switch connections and onwards to the battery terminals, fuse if fitted, and so on. Could be just about anything to be honest.

There's maybe someone up your way who can advise?
The Vandal
Member
Posts: 79
Joined: Fri Sep 16, 2022 7:43 pm
Location: West Sussex UK

Re: Lights, capacitors, action.

Post by The Vandal »

Groily wrote: Tue Feb 28, 2023 6:01 pm What happened to the 7.5v you reported way back? I suppose they've gone awol?
Was that output from the battery leads when I revved the engine? I'm still getting that, 2-3v on tickover, 7ish when I blip the throttle, just shy of 8v was the max I saw today when revving.
Groily wrote: Tue Feb 28, 2023 6:01 pmDoes ANYTHING light up if you turn anything at all on with the battery disconnected? If not, no output or wiring problem.
I want to say yes but I'm not 100% sure it does if I don't have the battery connected. Will try it.
Groily wrote: Tue Feb 28, 2023 6:01 pmYour battery voltage readings = "Beyond Dead Flat". Seriously, it's Zilch Squared.
The 2.9 vs 2.5 may be just because the battery was warmer after 60 miles, or because the voltmeter isn't that sensitive.
Got you, I'll try it again when I get back from work and see where it's at, more out of curiosity than anything.
Groily wrote: Tue Feb 28, 2023 6:01 pmYou have to go back to basics here, and start again with the dynamo-only tests, then (if the dynamo is putting out volts still when tested with D and F joined etc etc) move up to the regulator and the A wire output test again. Then check the ammeter / switch connections and onwards to the battery terminals, fuse if fitted, and so on. Could be just about anything to be honest.

There's maybe someone up your way who can advise?
That'd be good but I don't know if there's many in the club on the West coast, I've gotten the impression there's maybe a few Fife-y direction.
SPRIDDLER
Member
Posts: 8542
Joined: Wed Sep 01, 2004 1:00 am
Location: WEST SUSSEX UK

Re: Lights, capacitors, action.

Post by SPRIDDLER »

The Vandal wrote: Tue Feb 28, 2023 9:00 pm I'm still getting that, 2-3v on tickover, 7ish when I blip the throttle, just shy of 8v was the max I saw today when revving.
Far be it for me to try to add to Groily's wise advice, but.............

If you're getting 7 to 8V at the battery leads when blipping the throttle it would seem that:

a). The dynamo may be working as it should, although you should get a decent current reading (Amps) when using the Amps setting on a test meter (with a load applied) as well as a voltage reading when on the meter's voltage setting.

b). The regulator seems to be working otherwise when the revs rise above tickover the voltage would rise as the revs increase to well above 7 to 8 volts, perhaps to something approaching 15 or even 20V. (Check by doing the D and F test on the dynamo with a load applied). A charging rate of 7 to 8V is what the regulator will be set at (for a 6V system) to limit the charging voltage to prevent an overcharge voltage which would cause bulbs to blow / battery heating up / boiling over / bursting etc.........

My guess is that the battery may be stuffed due to suffering sulphation or distortion of the plates, especially if has been down to around 2.3V several times or for a long period, which may be why when the revs drop to tickover and the regulator cut-out disconnects the dynamo from the battery (as it should) you're only getting a reading of the low battery voltage.

Or it may be that the leads aren't making a good connection to the battery terminals so although the dynamo is putting the right charging voltage into the wires to the battery it isn't going into the battery.
However the fact that you don't seem to get any Amps showing on the test meter needs investigation.
'There is a tide in the affairs of men
Which taken at the flood............'
Groily
Member
Posts: 2151
Joined: Thu Jul 04, 2002 1:00 am
Location: NORMANDIE FRANCE

Re: Lights, capacitors, action.

Post by Groily »

The Vandal wrote: Tue Feb 28, 2023 9:00 pm
Groily wrote: Tue Feb 28, 2023 6:01 pm What happened to the 7.5v you reported way back? I suppose they've gone awol?
Was that output from the battery leads when I revved the engine? I'm still getting that, 2-3v on tickover, 7ish when I blip the throttle, just shy of 8v was the max I saw today when revving.

YUP, those were the ones I was thinking of - regulated output. Seems you may still be getting it - so that's a good start! Charging bits may still be good
Groily wrote: Tue Feb 28, 2023 6:01 pmDoes ANYTHING light up if you turn anything at all on with the battery disconnected? If not, no output or wiring problem.
I want to say yes but I'm not 100% sure it does if I don't have the battery connected. Will try it.

With engine running above tickover, that is.
Groily wrote: Tue Feb 28, 2023 6:01 pmYour battery voltage readings = "Beyond Dead Flat". Seriously, it's Zilch Squared.
The 2.9 vs 2.5 may be just because the battery was warmer after 60 miles, or because the voltmeter isn't that sensitive.
Got you, I'll try it again when I get back from work and see where it's at, more out of curiosity than anything.
Groily wrote: Tue Feb 28, 2023 6:01 pmYou have to go back to basics here, and start again with the dynamo-only tests, then (if the dynamo is putting out volts still when tested with D and F joined etc etc) move up to the regulator and the A wire output test again. Then check the ammeter / switch connections and onwards to the battery terminals, fuse if fitted, and so on. Could be just about anything to be honest.

There's maybe someone up your way who can advise?
That'd be good but I don't know if there's many in the club on the West coast, I've gotten the impression there's maybe a few Fife-y direction.

Oh well, you're stuck with us here then! But could well be a bad battery connection, or at the ammeter, as says Spriddler . . . Even if the battery has died, with it in circuit wired correctly you should (probably) see something, however modest, happening at the ammeter. And the lights should work with the engine running.
The Vandal
Member
Posts: 79
Joined: Fri Sep 16, 2022 7:43 pm
Location: West Sussex UK

Re: Lights, capacitors, action.

Post by The Vandal »

Well, everyone here has been very helpful so far so thank you!

This morning's results,

No battery in the circuit and nothing else between the battery leads, lights will still come on if I blip the throttle.

The f & d leads from dynamo to reg have bullet connectors on them so I disconnected the these and checked the voltage coming straight from the dynamo, 1-2v. Is it right that it's not the 7-8v at this point?

Found a bicycle dynamo light designed to work on 6v that has a couple fly leads so connected that up in place of the battery so +ve battery lead>lamp>meter>-ve battery lead and not getting any current readings on that so I think that removes the battery being goosed as the reason that I was unable to measure a current with it where the lamp is in that circuit.
User avatar
Pharisee
Member
Posts: 1126
Joined: Tue Mar 15, 2016 8:51 pm
Location: Lincolnshire UK
Contact:

Re: Lights, capacitors, action.

Post by Pharisee »

The Vandal wrote: Wed Mar 01, 2023 10:48 am The f & d leads from dynamo to reg have bullet connectors on them so I disconnected the these and checked the voltage coming straight from the dynamo, 1-2v. Is it right that it's not the 7-8v at this point?
Just to be sure that you're measuring it correctly, the F & D sockets on the dynamo should be connected together and you measure the voltage between that junction and earth/ground/frame when the engine is running.
John
I'm from the Fens.... Gimme six.
The Vandal
Member
Posts: 79
Joined: Fri Sep 16, 2022 7:43 pm
Location: West Sussex UK

Re: Lights, capacitors, action.

Post by The Vandal »

Ah ok, no I was measuring between the leads.

Probably won’t get a chance to redo that today but will soon.
Groily
Member
Posts: 2151
Joined: Thu Jul 04, 2002 1:00 am
Location: NORMANDIE FRANCE

Re: Lights, capacitors, action.

Post by Groily »

A.
i) If the lights come on with the engine running and brighten to full power with revs, then the charging system is working.
ii) Juice is obviously getting to the switch or the lights wouldn't come on.
iii) This says the 'A' wire from the regulator is getting to the switch OK.
iv) If the battery isn't being charged, then the juice isn't getting as far as or beyond the ammeter; isn't making it down to the battery; or if it IS getting there, the battery isn't earthed properly the other side.

With the battery out of circuit you wouldn't see anything register on the ammeter - as it's purpose is to show what is happening TO the battery.

B.
The 'Don't Knows' are therefore these:

i) Is the the A wire link between ammeter and switch in place and good? (See wiring diagrams provided previously.)
ii) Is the wire from battery to ammeter continuous, especially at any bullet or snap connectors en route? If not, nothing will get to the battery. You can test with the engine running with your meter on the DC volts scale, with one probe on the battery live side wire, the other to a good earth. Should see your 7+ volts at modest and higher rpm. (Battery out of circuit.)
iii) Is the battery earth connection good, at the battery terminal and at the frame (bare metal and shiny needed here)? If not, the battery won't charge even if it's getting supplied on the live side.
iv) Is/are any fuses and fuse-holders in either of the battery leads good?

You need to run a meter on the resistance scale from end to end of these wires (and across any fuses) to make sure they are connected, seeing Zero ohms from end to end or as near as.

Given that everything apparently works, except for the fact that the battery isn't charging, the fault is almost 100% sure a simple wiring one - unless something unusually horrible has happened to the battery itself.
(I am assuming the battery is hooked up the right way round.)

Suggest you check the 'Don't Knows' above to be sure the circuits are continuous, then refit the charged battery with the live and earth the right way round, and see how it does.
The Vandal
Member
Posts: 79
Joined: Fri Sep 16, 2022 7:43 pm
Location: West Sussex UK

Re: Lights, capacitors, action.

Post by The Vandal »

Groily wrote: Wed Mar 01, 2023 4:06 pm A.
i) If the lights come on with the engine running and brighten to full power with revs, then the charging system is working.
Yup, this happens with or without the battery in the system so that's positive.

Groily wrote: Wed Mar 01, 2023 4:06 pmii) Juice is obviously getting to the switch or the lights wouldn't come on.
iii) This says the 'A' wire from the regulator is getting to the switch OK.
iv) If the battery isn't being charged, then the juice isn't getting as far as or beyond the ammeter; isn't making it down to the battery; or if it IS getting there, the battery isn't earthed properly the other side.
If the battery wasn't earthed properly would I still be seeing good voltage when I have the meter in place of the battery?

Groily wrote: Wed Mar 01, 2023 4:06 pmWith the battery out of circuit you wouldn't see anything register on the ammeter - as it's purpose is to show what is happening TO the battery.
The only movement I've gotten from the ammeter recently (last couple rides) has been moving to the '+' side when applying the rear brake and illuminating the brake light. Switching side/head lights on/off doesn't cause it to move, neither with engine shut off, at idle or while moving ie revs up.
Groily wrote: Wed Mar 01, 2023 4:06 pmB.
The 'Don't Knows' are therefore these:

i) Is the the A wire link between ammeter and switch in place and good? (See wiring diagrams provided previously.)
ii) Is the wire from battery to ammeter continuous, especially at any bullet or snap connectors en route? If not, nothing will get to the battery. You can test with the engine running with your meter on the DC volts scale, with one probe on the battery live side wire, the other to a good earth. Should see your 7+ volts at modest and higher rpm. (Battery out of circuit.)
iii) Is the battery earth connection good, at the battery terminal and at the frame (bare metal and shiny needed here)? If not, the battery won't charge even if it's getting supplied on the live side.
iv) Is/are any fuses and fuse-holders in either of the battery leads good?

You need to run a meter on the resistance scale from end to end of these wires (and across any fuses) to make sure they are connected, seeing Zero ohms from end to end or as near as.

Given that everything apparently works, except for the fact that the battery isn't charging, the fault is almost 100% sure a simple wiring one - unless something unusually horrible has happened to the battery itself.
(I am assuming the battery is hooked up the right way round.)

Suggest you check the 'Don't Knows' above to be sure the circuits are continuous, then refit the charged battery with the live and earth the right way round, and see how it does.
I found a photo on my phone from January that I'd taken of the bike stationary and the headlamp is on. Obviously from a photo I can't tell if the engine is off or idling but I can tell that as recently as that the battery was charged enough to run the headlamp. Battery was bought in September so I don' think it could have been running off the remains of an original charge at that point.

I'll check the battery earth but would I be getting the 7-8v on the meter if the earth was bad?

I'm thinking that it's maybe still the wiring with the ammeter and the headlamp switch so going to have to revisit that and check it all again.
Post Reply