Wiring

[yorkie_chris]

After stuffing my bike on wedsday it won't start, appear to have lost the ignition hot wire somewhere.

So, since every month since I've had it it has decided to lose a curcuit somewhere, brake lights, ignition, starting circuit.. etc. I've decided to rewire it, cutting out as many unnecessary circuits as possible to keep it simple-ish.
I'm basically sick of suzukis cheese-wires corroding for fun.

Going to get the wire and connectors from vehicle wiring parts unless anyone knows a better place? ...or indeed has a better suggestion

Chris

[Ruffy]

Going to get the wire and connectors from vehicle wiring parts unless anyone knows a better place? ...or indeed has a better suggestion


I presume you mean Vehicle Wiring Products in Ilkeston. I think this link is right:
www.vehicle-wiring-products.co.uk (http://www.vehicle-wiring-products.co.uk)

I've used 'em before a few times and they've been fine - service is good, prices seem to be competitive. Some of their kit options may be more cost effective for a full rewire.

From my experience though, I'd suggest using the uninsulated terminals and boots rather than the more common red/blue/yellow crimps. A bit more fiddly to put together, but should be less vulnerable to vibration once back on the road.

[dirtydog]

What about sticking another loom on there? You can get them from www.svspares.com (http://www.svspares.com) for £25

[yorkie_chris]

Another question here, jsut looking at haynes and somethings got me confuddled, what is the clutch diode?
Can't understnad the reason for its existence or why the starter trigger would have a diode accross it, unless it's a peculiarity of the way the relay works...?

I'm looking at haynes SV manual page 9-36

Anyone else have a clue why this thing is there, and also where is it on the bike?

Chris

[Alpinestarhero]

Another question here, jsut looking at haynes and somethings got me confuddled, what is the clutch diode?
Can't understnad the reason for its existence or why the starter trigger would have a diode accross it, unless it's a peculiarity of the way the relay works...?

I'm looking at haynes SV manual page 9-36

Anyone else have a clue why this thing is there, and also where is it on the bike?

Chris

I think I came across this the other day, I pointed at something and my dad said it was a diode, i think he mentioned it was for the clutch - but the engine was running at 5000 rpm so i didnt hear properly. Anyway, the diode in question was in the area of the voltage regulator / rectifier, on the subframe. The best description of it I can give is a connector with a stubbly thing connected

Might be of some help to you, sorry if its not...

Matt

[yorkie_chris]

I know what it is, it's what it does thats confusing me lol

(obviously stops current flowing in one direction, but there's no current there to stop as it goes to earth...)

Edit: No I'm wrong, it stops current flowing from the starter trigger wire to earth, but in that case, why put a wire there at all?

[Alpinestarhero]

I know what it is, it's what it does thats confusing me lol

(obviously stops current flowing in one direction, but there's no current there to stop as it goes to earth...)

Ohhh i see, gotcha

Well, i know nothing about electronics...so I'm stumped

Matt

[yorkie_chris]

Balls to it, I'll build the new loom without and see if it goes bang.

[Alpinestarhero]

Balls to it, I'll build the new loom without and see if it goes bang.

Thats the way to do it. Problem with electronics is that a large hammer cant be used to sort the prob.

Matt

[yorkie_chris]

Want a bet? :p

[Alpinestarhero]

Want a bet? :p

LOL :p:D

Matt

[yorkie_chris]

What about sticking another loom on there? You can get them from www.svspares.com (http://www.svspares.com) for £25

Not going down this route as some of the faults have been on the component side of the connectors, i.e not the loom itself. Just rotten connectors and wires.

[Ruffy]

Another question here, jsut looking at haynes and somethings got me confuddled, what is the clutch diode?
Can't understnad the reason for its existence or why the starter trigger would have a diode accross it, unless it's a peculiarity of the way the relay works...?

I'm looking at haynes SV manual page 9-36

Anyone else have a clue why this thing is there, and also where is it on the bike?

Chris

Sorry haven't got a Haynes manual, but did have a scan at the wiring diagrams I downloaded off the .org site.

It looks like this diode is what's affectionately termed a 'freewheel diode'. It's connected in parallel with the starter relay coil and is there to discharge high voltage build up when the relay coil is de-energised.

If you want the theory, I'll try to explain: when you energise the main starter relay (via starter button/clutch switch/starter control relay), the diode won't conduct as it's connected the wrong way, so no short to earth. All that happens is the relay coil energises and the relay pulls in, fine and dandy. However, when the start switch is released, thanks to the inductance of the wound relay coil, a high voltage of opposite polarity is produced, trying to stop the reduction of electrical current in the coil. This induced voltage wants to keep the current flowing. By connecting a diode in reverse polarity across the coil, the current can discharge itself through the relay coil without affecting other parts of the wiring (hence 'freewheeling'). Because all this is happening in milliseconds and electricity is basically lazy, it stabilises the system to prevent adverse effects on other parts of the wiring. Think of it a bit like a soft-off.

The induced voltage can be hundreds of volts and, in the absence of the diode, is often enough to produce sparking across switch contacts or enough to zap electronic components that may be connected nearby. (It's basically this principle that's used in a car distributor/coil arrangement to produce sparks at the plugs.)

I can't believe the starter relay coil is that meaty so, without the diode, it's unlikely to go bang straight away, but it will probably start playing up eventually, maybe when the start switch contact has been spark eroded (ie. burnt) away.

Personally, I'd leave it in - remake the connector ends for reliability if they're a cause for concern, but don't disconnect it just yet!

[yorkie_chris]

Ahhh, I'll wire it in then.
My wire and connectors should be with me tomorrow so I can get started.


It's basically this principle that's used in a car distributor/coil arrangement to produce sparks at the plugs.

And the SV, the ignition control unit switches a transistor to cut the earth to the coil.

[Ruffy]

And the SV, the ignition control unit switches a transistor to cut the earth to the coil.

Yep, you're right of course. When I wrote the original post, I was thinking of the dizzie being like a set of mechanical switches but an electronic ignition does exactly the same thing. The coils produce the inductive effect on all in just the same way - they react to step changes in voltage.

Best of luck with the wiring, hope the reliability improves.

[yorkie_chris]

Me too, damn suzuki cheese-wiring, all been ripped out to be replaced with insulated spades washed and soaked in ACF50, sealed in tubing, if this corrodes I'll cry!

[krazdndenver]

The diodes, there should be three of them. They change the AC voltage from the generator to DC current to run the bike. I believe they are internal in the reg/rect. You need these. As far as making a harness I use either non insulated connectors with dielectric grease and shrink rap to make butt conections. If you need to make a connection that can be separated I would use GM weather Pac connectors. They make a sealed connection, but you should use the special crimping tool for these, I also solder all connections for good conductivity.

[yorkie_chris]

The reg/rec, well the "rec" bit anyway is just a diode pack, rectifies the 3phase alternator output to DC which then gets regulated to 14v or whatever to charge the battery.

We're on about the thing labelled on haynes wiring diagram as the "clutch diode" which is a diode on its own just below the reg/rec in the loom, turns out to be a soft off for the starter relay as ruffy explained.

chris

[Ruffy]

The diodes, there should be three of them. They change the AC voltage from the generator to DC current to run the bike. I believe they are internal in the reg/rect.

If you were able to break one down, I think you'd find there's actually six diodes in the rectifier!

As yorkie-chris has said in his other post, it's a different diode he was concerned about, though.

[yorkie_chris]

Just getting started on this here loom, and I must say:

AAAAAHHRRRG!

What a ####ing boring, painful #### of a job.

:smt097

Love Chris

[Ruffy]

Just getting started on this here loom, and I must say:

AAAAAHHRRRG!

What a ####ing boring, painful #### of a job.

:smt097

Love Chris

But it's one step closer to being back on the road... ...the one that takes you to the pub whenever you want!!!

Last time I re-wired a bike, I seem to recall that I found creating the basic loom OK but it was crimping all the connectors that really hacked me off in the end.

Stick at it, Chris. Then you'll soon be able to look back and say 'thank **** that's finished, I'm off out for a blast'.

[yorkie_chris]

Getting there, ignition hot turns on when it should, and the starter circuit works (turns over ok) just need to check for sparks tomorrow.

Also a recomendation, adhesive backed heatshrink tubing is excellent stuff, you burn your fingers a bit, but as far as I can see its left a lasting seal. Slightly more ££ than normal heatshrink, but looks worth it.

Now then, onto the signals circuit....