Bike electrics head scratcher.

[SteveR]

I am having a bit of a 'mare trying to suss out an issue with starting on my Honda NX400, for those not familiar with my girl, it's a sanitised trailie version of a Honda XR400! Proper seat and electrics etc etc

So, the problem... For some time she has been a reluctant starter, showing all the sign of either a poor terminals connection or a ropey starter solenoid, occasional reluctance to fire and just a single click from the solenoid.

I have got a good, fairly new battery on it, I've checked all the main lead connections recently, and I got hold of a new solenoid a few weeks ago ready to pop on when I have a moment. Last night was that moment, so after the usual push, click, nothing, I wheeled it to the car port and got spannering, as I wanted a ride later in the week!

Before working on the bike, I had a neutral light on the dash, so ignition was working.

I swapped the solenoid out for the new one, and found EVERYTHING was out, no starting, no ignition light coming on, nada, nothing! Checked all the connections, checked fuse, pushed the block connector on and off a few times to be sure of a good contact, nothing.

So, in case of a dud replacement solenoid, I put the old one back one. Still nothing and more worryingly, still no power to ignition circuit and no neutral light.

So checked all connections were good, checked I'd got the leads on right way!! and all fuses etc were good. Still no joy, the whole system is dead. By this time, I was running out of light, so pushed her back into the container, locked up and went off to ponder the problem.

After a nights sleep on it, I am no wiser, all the wires etc look fine. Battery is fully charged, I did nothing other than take the solenoid off and replace it, after which when the problem arose, I started checking leads etc...

So, any thoughts, advice or ideas from anyone please?

[SteveR]

I am starting to wonder if it's the ignition switch itself, but find it hard to see why it would suddenly fail after working on the solenoid??

[diggermanbob]

Steve is there a main loom connector for all the dash and controls etc , usually under the headlamp cowl area , !!

[SteveR]

Steve is there a main loom connector for all the dash and controls etc , usually under the headlamp cowl area , !!

I imagine so Bob, not got to the front end yet...

You are thinking bad connection there?

[diggermanbob]

Steve is there a main loom connector for all the dash and controls etc , usually under the headlamp cowl area , !!

I imagine so Bob, not got to the front end yet...

You are thinking bad connection there?

Yes that's what I was thinking as you have had problems with starting maybe just a bad connection in the main block.

[SteveR]

Had all the connectors apart and back together a few times. Also pulled the wires and checked the ignition switch is working OK, it is.

I also checked power out of the battery to the starter by dropping a screwdriver across the solenoid terminals, worked fine

[bill_qaz]

A quick search shows a second 10amp ign. fuse as well as the main perhaps you have blown it?

NX250 wiring.jpg (33.43 KiB) Viewed 2738 times

[SteveR]

Thank you Bill, that circuit diagram is one heck of a lot clearer than the one I have on my computer, for starters its in English

I had found the second fuse earlier today, it is in the fuse box with two others. As with the main fuse, all seems fine.

It as if there is no power coming from the battery to the main fuse on the solenoid assembly and on to the ignition switch. There is not much to the system as far as I can see... Battery --- Solenoid/Fuse ---- ignition switch --- power back to solenoid that is then switched by the started button?

[AlanHolt]

Have you tried making a new earth connection from frame & engine to the negative side of the battery? I've known earth wires crumble to dust on old cars and bikes after giving lazy started symptoms.

[bill_qaz]

Have you got a test lamp or if not a 12v bulb and solder two wires? Put one on battery neg and then check the pos each step from battery to ign switch. Then put one on battery pos the other to check each earth, either way you should get a bright light