Classic Triumph Bonneville

[Count Steer]

Yeah I reckon its not charging. I did originally check it was charging but I'll lay odds its just shaken some aspect of the charging system loose.

Started struggling to rev and then progressively got worse before dying completely. I'm like 2 miles from home but it's all dual carriageway.

Shame you can't whistle up a get-you-home battery. I reckon you're going to have to thread-lock anything with a thread on!

[Mr. Dazzle]

Course....doesn't explain why its not charging.

Doubly gallijg in that I've broken down within earshot of the Jubilee Beacon lighting which would have been a shoe in for the "your bike at a..." thread. Can't get to it from here though.

[Mr. Dazzle]

RaC here now....

Battery reads 6V!

[JackyJoll]

Am I right in thinking you’re some sort of engineer?

Hope you’re a better engineer than you are a mechanic.

[JackyJoll]

Have you got breakdown recovery in your insurance as well, in case you use up all of your allowed RAC rescues?

It’s worth reading the small print, because some schemes only recover you to a motorcycle repair garage, who of course, know nothing about repairing an old Triumph.

[Mr. Dazzle]

RAC man charged me up for 15 mins then it was sort of OK.

"Sort of" because the first two times I started it, the died the moment I took it off the centre stand. The wiring is a fucking state, there has gotta be something shorting/not connecting properly in there. I reckon when you take it off the stand the suspension movement jiggles something.

We gave it a bit of a poke about and put tape over a suspect looking bare wire, then tried again...I got home just fine then.

The wiring is a proper mess, it's mostly reclaimed Ford Cortina with a touch of Halfords. Like I said, it was charging when I checked it recently, but evidently not any more.

That's not even the only break down I had this evening! I also lost the clutch lever bolt. Fortunately I don't need a fancy computer to ride without a clutch.

Half the problem here is that this bike hasn't been ridden in 10 years and hasn't been ridden above about 50mph/3500rpm in more like 25.

[JackyJoll]

More than once, I have rewired from scratch to simplify and rationalise the electrics and ended up with something at least as bad.

But good luck.

Glad to hear you’re at least manly enough to ride with no clutch.

[Mr. Dazzle]

Had a quick look this morning....one of the plugs which connects the alternator wiring to the harness is only just 'on' the wire and just came off in my hand. That certainly won't help

Loads of random coloured wires (i.e. not the colour the diagrams say they should be) with those red/blue/yellow crappy halfords terminals and exposed conductor. I already knew that of course, but still...

A whole new (Lucas ) harness is fifty quid. I am not sure what else I'd need to include though on account of the aftermarket ignition. I shall investigate.

BTW, as far as I can work out this bike doesn't actually need a battery to run. I say that because it's got a boyer electronic ignition and a boyer power box which boyer themselves say "is not intended to run with a battery". Said box has a capacitor in it which stores enough juice to allow you to run without a battery and just rely on the alternator and the little bit stored in said capacitor to smooth things out.

However, that's predicated on having power available from the alternator. I reckon I've been running with an alternator some of the time and running total loss the rest of the time. So the weirdest hybrid possible

The fact it died instantly when I moved it off the stand is a red flag that a wire is loose though surely.

[JackyJoll]

Some people manage with a Boyer ignition and no battery and claim they’re happy, but it’s marginal.

I wouldn’t have much faith in Boyer’s sales talk about magic capacitors.

My Wassell ignition is a sort of copy of a Boyer and my Alton alternator performs very like a Lucas 120W alternator. It will run with the battery out of circuit, but I can’t start it like that. Also, when it’s idling with no battery, switching the headlight on makes the engine cut out immediately.

[Mr. Dazzle]

I've no plans to remove the battery, if nothing else I want the option of headlights! Just saying it shouldn't have conked out on account of a flat battery.

All i need to do now is dedice how I'm gonna rewire it. The ignition, reg/rec, switchgear, idiot lights and key are all non standard in either design or location, so I'm wondering how useful an off the shelf harness would actually be.

The headlights and brake lights work even when the key's not in the ignition. How's that for silly. My FiL always used to take the main fuse out when parked

[JackyJoll]

The ignition is connected to the battery, through a switch and some wires. That powers the ignition.

If the battery goes flat, I really would expect the ignition to stop working.

The ignition can work (a bit) in absence of a battery, but the charging system has to be working, for that to happen. That’s the battery charging system, which in your case has not charged the battery.

[JackyJoll]

one of the plugs which connects the alternator wiring to the harness is only just 'on' the wire and just came off in my hand.

If that had lost contact it would explain the flat battery and subsequent loss of ignition.

[Mr. Dazzle]

My thoughts too. Its one of those shit Halfords terminals.

I think I'll get one of those crimping tools that does the proper 'edges folded over' terminals plus a load of heat shrink sleeves, then remake a bunch of joints. Its got about 17 miles of excess length so I can cut the wire back to a decent bit.

[JackyJoll]

The pre-insulated red and blue terminals, crimped with the tool that comes in the kit, are prone to loosen.

[JackyJoll]

The guy Stuart on Triumphrat had recommendations about which make of new wiring harness to buy. It might take some decoding because he’s a bit obsessive.

[DefTrap]

I do all my own wiring (I reckon 80% of stock wiring is a waste of effort and a liability) on old bikes anyway.
There was a chap called Ferret who was the biz for classic bike rewiring https://www.motorcyclewiring.co.uk/

[Mr. Dazzle]

That is simultaneously the best and worst website I've seen.

[JackyJoll]

I do all my own wiring (I reckon 80% of stock wiring is a waste of effort and a liability) on old bikes anyway.
There was a chap called Ferret who was the biz for classic bike rewiring https://www.motorcyclewiring.co.uk/

He’s quite famous.

Quite a lot of money is involved, if I remember what I read.

[Le_Fromage_Grande]

Ferret is good, or do it your self, if it has a battery it only needs 4 wires to run, 12V to coils, earth to points, points to coil, and engine earth, though if you want to be able to stop it easily a switch on the 12V feed to the coils is a good idea.

Not sure what the charging is on an old Triumph, but on most Japanese 4 strokes it's 3 wires from the generator to the regulator, then either 2 or 3 wires from that to the battery, earth, +12V and another +12V feed back wire.

Then a separate loom for all the road legal stuff like lights and horn.

[Mr. Dazzle]

Brake lights are kinda handy. Plus headlights for days like yesterday when I break down until after dark