Non stop starter

[Bamboo812]

^^^^ Wrong. Shorting across the two wires, big one from the battery positive and smaller one from starter relay does activate the solenoid and turn the starter, if everything is working correctly.

[jagarra]

I agree, about the heavy terminals. Went for a walk and was thinking about the problem, realized by shorting big terminals all one was doing was bypassing solenoid and checking starter operation. In this problem we have to pull the solenoid. it was a correct answer for not spinning, rather than spinning all the time. Not enough coffee yet before I answered.

So the small and large terminal are the ones we want as we are pulling the solenoid in that case.

As an side note. Best pull the plugs when you are doing all this testing, your current load will not be as great and a lot less sparking and arching will go on.



gg

[r75bitsa]

If you apply power to the spade terminal direct to the battery, without the switch involvement, it energises the solenoid. That's what happened, then when current is removed from the terminal it stopped. When I reconnected the black from the relay and used the switch it ran on. Wouldn't that then be either a grubby or stuffed switch or some other wiring gremlin.

[jagarra]

Now you're on the right track. Looks like the problem is in the switch or the relay. If you have an ohm meter you can check the switch to see if it is sticking or the internal spring may be broke. If you don't have a meter, you have to energize the relay from another source. If you can figure out which wire to the relay comes from the switch disconnect the wire and I would touch that terminal to 12v via a jumper wire. If motor stops when you remove the wire the switch is all that is left. Relays very rarely go bad, the switch is the most likely culprit.

[r75bitsa]

Is that just checking the connections behind that plastic shield, cleaning and maybe replacing whatever. I imagine you have to remove that little circlip thingy very carefully that is on the kill switch peg and go from there in the guts of the switch block.
Thanks for all of the advise and confusion look forward to replies.

[jagarra]

Do you have a meter so that you can check the switch?

[r75bitsa]

Certainly have. How technical do I have to get.

[jagarra]

figure out which wires go from the start button to the relay, check for continuity on the ohms scale. if the switch is working correctly, you should see it go from a short to an open when it is pushed in then released. Ignition does not have to be on to do this test.
Probably easiest to find them at the relay end. According to my schematic, it may be the Brown wire with light brown tracer. The other wire off the switch is blue with a yellow tracer. the blue/yellow ones goes to the clutch interlock, may end on ground. The only one of those that makes it to the relay is the Brown/tan one.

My schematic is also for a 75/6 so it may be slightly different.

[Snakeoil]

First, the comments below in italics are what I thought was going on and started to give you a step by step. It might still apply so I'm leaving it here in case what I'm about to say is not the cause.

While I was looking at the wiring diagram and understanding how the starting circuit works, I noticed something inside the starter motor/solenoid portion of the diagram. The 12v power that runs thru the solenoid contacts to power the starter motor, is also electrically connected on the cold side of those contacts to the coil in the solenoid. Unless the diagram is misleading, that cannot be. This is the same issue I ran into with that Harley many years ago.

When the solenoid closed, it put's 12vdc to the cold side of the contacs and in turn to the motor. But based on how the diagram is drawn, it also puts 12vdc to the coil in the solenoid. That would seal the solenoid closed.

Now you can test this quite simply. Remove the relay wire, which is black, between the relay and the solenoid. Now, connect the solenoid terminal that brings battery power to the solenoid to the relay feed terminal on the solenoid. This will energize the solenoid and energize the motor. When you remove the jumper, the motor should stop. If it doesn't, some will say the solenoid is sticking. I'm telling you that it is electrically sealed in. When you remove the battery cable it will open the solenoid and unseal it. Look at your wiring diagram and you will see the wire between the cold solenoid contact and the solenoid coil. A solenoid is just another type of relay. So look at the other relays on the diagram and you will see that the cold contacts on the relay are never wired to the power feed to the relay coils.

If the test above results in the opposite. By that I mean the motor stops when you remove the jumper because the solenoid opens, then the diagram is misleading and you should read the suggestions below. But I still think you have an electrical error and something is sealing in either the relay or the solenoid because removing power should not unstick a mechanical problem.

Find the wire that goes from the switch to the relay. Disconnect it at the relay. From my diagram that appears to be a blue/yellow wire. This wire provides a ground to the starter relay coil, which energizes the relay coil, closing the contact and providing a complete circuit to the solenoid, which in turn closes and provided power to the starter.

So, with the blue/yellow wire off, connect the DMM to the wire and to a known ground on the bike. Set the meter to ohms. When you push the button it should go to zero ohms and when you let go, should return to infinity which is normally full scale on a DMM display.

I'm willing to bet that your switch is fine. I say this because if the switch were sticking, when you removed the battery cable and then reconnected, the starter should start running again. But it doesn't. Removing power from the circuit should not affect a mechanically sticky switch. But go ahead and test it because that is the only way you will prove that the switch is not the cause.

With that done, let's move to the starter relay. Reconnect your starter button blue/yellow wire to the relay. Remove the black wire from the solenoid that comes from the relay. This is the wire that makes the solenoid open and close. Make sure you insulate it with a piece of rubber tubing or tape because when the relay is energized, that wire carries +12v to the solenoid. Now push the starter button with your finger on the starter relay to feel it click closed. You probably can hear it as well if you turn the radio off in your shop. Let go of the button and the relay should click again as it opens. It may be very hard to hear or feel the opening click. So, push the button again to see if it clicks closed again. It should. If it doesn't then it is sealed closed or stuck. Again, I doubt it is stuck if removing the batter cable clears the problem.
If it does not click open and closed, but just closes and stays closed, you can confirm that by putting your DMM set to Volts DC and connecting the red lead to the wire end that came off the solenoid and the other end to a known ground. When you push the button, the relay should close and you will read 12 VDC. When you let go, the relay should open and you should read 0 VDC. If you read 12VDC one the button is pushed and when you release it, the 12VDC remains, the relay is still closed.

At this point, to confirm it is not the button, pull the blue/yellow wire off the relay and see if the relay opens. It will if the button is stuck. But again, I don't think the button is stuck.

So, if the relay is staying closed when the button is released, then that is the root symptom for your problem. But you have not found the root cause yet.

I really think you have a wiring error.

Hope this was helpful.

regards,
Rob

[r75bitsa]

Thanks mate with that wealth of information iam either going to consume a six pack in the process or find it straight away. Will tackle it tonight. Regards.