Not idiot proof - ignition circuit problem

[brucebayliss]

So, put the bike (Yamaha SRV250) back together and no neutral light, no start. Indicators, headlight & horn all OK.Turns out the plugs in the headlight cluster weren't as idiot proof as I assumed; in the process of a bit of a re-furb, I have transposed a couple of plugs (I think maybe the right & left control plugs).

I check the fuses and the 5 amp ignition plus 15 amp head & signal fuses have blown. There were no problems before I disconnected everything and pulled the headlight out to treat rust.


I've checked continuity to the best of my limited ability & cleaned connections. Suspect I have melted a component such as cut-off relay or igniter unit.

Is there a "most likely suspect" in this scenario?

Thanks in anticipation.

Bruce

[notme]

Indicators, headlight & horn all OK.

the 5 amp ignition plus 15 amp head & signal fuses have blown.

Interesting...headlights and indicators working but their fuses are blown?

A wiring diagram is really needed to help with this one - find one and mark the plugs you might have swapped and we can go from there. You could blindly check relays, diodes etc and maybe get lucky, but a wiring diagram will help a lot!

[brucebayliss]

Sorry; got my sequence wrong - fuses were blown and nothing worked. Now, I think all fuses are OK and ignition circuit still unresponsive.

I have a wiring diagram and will take a fresh look this morning.

Cheers.

[notme]

put up a scan or photo of the diagram.....

[brucebayliss]

Here's the diagram. I transposed the two six-wire blocks at #40 (right handlebar switch) and down between #25 & #24 (left handlebar cluster).

Thanks for the response.

[notme]

This could be bad...as in dead igniter unit. Swapping those 2 plugs puts voltages all sorts of places that it should not be!

Just in case you have been lucky:

1. Check EVERY fuse if you haven't already. Test them rather than a visual inspection...
2. Test the diode at number 9. Hopefully you have killed it and nothing else

[brucebayliss]

Hi Allun,

Fuses all OK. Diode OK too I think (measures 0.488). You don't think it could be cutoff relay (still trying to figure out testing continuity on it)?

May be igniter as you say...

[notme]

Bugger. The first couple of things I suggested were the easy to check and most obvious things that it might be.....from this point on it might be quite hard to troubleshoot over the net and might need to be taken somewhere. Sorry mate.

By swapping the plugs accidentally, currents have flowed where they should not, and there could be something as simple as a dead relay, or it could be multiple point failures all thru the system.

The LHS switchblock has the headlights and horn and clutch disable switch and so on, the RHS has the start button and kill switch and brake switch - swapping the 2 will have made all sorts of thing potentially go wrong.

If you want to check more stuff yourself, at this point i would recommend taking every relay out and testing for operation (i.e. power the coil with 12V and make sure the relay clicks).

[brucebayliss]

Hey thanks Allun - appreciate the advice. I'll post the result!

Cheers,

Bruce

[brucebayliss]

Hi Allun, finally got around to fixing this and you were spot on - it was the CDI box. Ordered a second hand one from Japan and the bike came to life! Still no neutral light (lamp has continuity) and have to start with clutch in so I must have buggered that switch too - will look at that later in the week.

Thanks for your help.


Bruce

[notme]

Good to hear there's been progress :-)

With the clutch/neutral issue - you can see on the diagram you posted that the neutral light circuit is quite simple - the light is fed (along with indicators and brakes etc) from the fuse (38), and the neutral light will light up and signal the igniter unit when it is grounded through the neutral switch (15).

If your indicators and brake lights work, fuse (38) can't be blown, so that only realistically leaves the neutral switch, bulb, or a connector along the way. You said the bulb has continuity, and i'm sure you'd notice if all the other signal lights were not working either, so that only leaves the switch or some wiring somewhere.

Check to see there is 12v across the switch in one position and 0v in the other...