Ignition problem when in gear. Neutral or clutch or sidestand problem?

[radiance]

Hello!

I am new to the forum, I have just introduced myself in the appropriate section. I've been very happy with my 2001 ex-police ST1100 so far (owned for 5 months), I am just experiencing one electrical problem that leaves me a bit baffled. I've had a search on the forum but this issue of mine seems to be new:

I used to be able to start the bike in any gear in if I pressed the clutch and the side stand was up.

Since a few weeks I cannot start the bike like that anymore: I press the clutch (I hear the tick of the clutch switch), the sidestand is up (the 'S' light on the dash goes off) with any gear engaged (the 'N' light is off) but the bike doesn't fire up. If I put in neutral again (the 'N' light goes on), it fires up. So the neutral and the sidestand sensors seem to be working fine, no?

I am no qualified auto electrician but I know a few fundamental bits and bops from DIYing...So the other day i removed the two pins connected to the clutch switch and measured if any of the two received current (so that the switch closes the circuit when engaged and current can flow)... I surprisingly discovered that current comes to one pin only when the bike is in NEUTRAL. When the bike is in a gear, no current arrives to any of the two pins.

Now, shouldn't it be the other way round? Shouldn't current be present at one pin when the bike is in gear so that the clutch switch (by letting current flow or not) can indicate whether the clutch lever is pulled or not?

What could the problem be in this case?

Thank you in advance for your help!#

Karol

[spanner]

funnily enough I have this same problem.

I used to be able to start in any gear with side stand up but now can not.

I have no investigated any further because I keep forgetting but on this last trip down south it became a bit frustrating.

Would love to hear any fixes in this regard as well.

[Brock]

It probably is the clutch switch.

You dont measure the current, but voltage. ( technical picky thing, cos I am an aero electrician), havent tried any testing thing there.

Its all about placing an earth on the sensor for the gearbox I think, I need to get a new clutch switch as well, as mine sometimes plays up as well. I usually just click in to neutral and away it goes.

[Biggles]

So the switch is clicking but not switching?

[Yorkie]

The clutch, neutral and side stand switches complete the earth circuit enabling the start relay to energise.

[radiance]

There's one thing that scares me about this restart problem, which is, finding myself in a dangerous situation on the road when the engine has accidentally stopped and it needs to be restarted ASAP. So yesterday I took some time to get this thing sorted. 

Apparently there is a clutch diode located somewhere along the wiring under the tank cover (picture attached - not sure if you guys are referring to it as the 'clutch switch'). It is taped to the wiring loom and a bit hard to see at the beginning. I removed the tape, removed the clutch diode, cleaned the contacts and put the diode back on.

Works perfect now. Fires up when in gear every time without hesitation.

Now I don't know exactly how this diode works (because it's got 3 pins instead of 2 ), but my theory is that it ended up operating in the opposite way to what it should have done, that's why it it was sending current to the clutch switch (the one under the gear lever) when the bike was in Neutral, not in gear.

[spanner]

Nice job radiance
!

[Biggles]

Apparently there is a clutch diode located somewhere along the wiring under the tank cover (picture attached - not sure if you guys are referring to it as the 'clutch switch').

Nah- I was referring to the mechanical switch at the lever.
That's the first time I've heard of that diode.  Will be interesting to read what Brock thinks when he gets out of bed.

[hobs]

I have a micro switch at the clutch master cylinder. Operated when you pull the clutch lever in. Thought that was the switch to allow start. Is this part of the circuit? Mine is a1996 ex Police.

[Gadget]

Three pin diode? Hmmmm.... :thinking
I wonder if it is back to back diodes or.......
If the three pins are so it can't be put in the wrong way around.
I suspect that corrosion had built up on the connectors causing an effectively, open or near open circuit.
Glad you solved it.

[Brock]

I am perusing the circuit, trying to work out what is happening.

What the system does, is makes it not possible to start the bike in gear, and/or the sidestand down.

To start with sidestand up and in gear, clutch needs to be pulled in.
To start with sidestand up and in neutral, just press the button.
To start with sidestand down and in gear, not going to happen..
To start with sidestand down and in neutral, just press the button.

The diode is used to detectect neutral and clutch in/out and tell the spark control module what to do. Just need to have a rest and work out how.

[saaz]

Sorry to be late on this, but the diode is a known issue with age. Usually goes before the switch. I have had the brake switch play up, but using lots of contact cleaner and working the switch made it work just fine.

[Pezzz]

Mine does the same thing. Been a bit annoying on this trip but keep forgetting about it when I have covers off. Will have to remember next time. I need all to align to start the bike most times. Clutch in, bike in neutral, and side stand up.
Can make it fun on a hill .....

[spanner]

that's why the pendel parking break is so good!

[alans1100]

I just leave mine in neutral, turn key on, press start and it goes.

Sometimes I forget neutral and wonder why the motor stops when I put the stand down. Absent minded way to check if the side stand switch is still working.

I did a test with run switch once (and left it off) and it took me a couple minutes to work out why I couldn't start the thing up. (age related STML)

Otherwise, side stand up, in gear, clutch in and it starts up as far as I can remember back to the last unplanned engine stop.