Brian UK said:It is effectively the same thing as adding an extra wire from the battery positive terminal (I personally don't like tapping into existing wires),
Wayne Orwig said:Bill Hagan has, or hopefully had, a starting issue on his Norge.
The short version:
He was getting 6.4 volts to the solenoid. He now had just under 10 volts there. Hopefully, that is the cure for his problem.
The long version:
I believe this started one year ago, on the way to the Virginia rally. It was intermittent. And debugging over a cell phone never works well. I don't believe that it was blowing the 15 amp starter solenoid fuse very often, but it did occasionally. And most of the time Bill stated that the starter relay was NOT clicking. So we thought it was upstream of the relay.
So through the winter, there were few or no issue. Then the Virginia rally comes around for this year, and it was again a no start. This time around I got to actually touch it when it was failing. The starter relay WAS actuating, but the starter solenoid was dead. And often the 15 amp fuse would blow.
Today I looked into it finally, and this is what I found.
Using a 1 ohm resistor and the 12 volt bike battery, I passed a lot of current through the system parts and made some rough resistance measurements.
From the battery, through the 30 amp fuse and the wiring harness, through the ignition switch, and back under the seat to the 15 amp fuse, is about 0.1 ohms total. Through the 15 amp fuse and the wire to the relay is about 0.06 ohms. From the relay to the starter solenoid is about 0.03 ohms. Total is about 0.19 ohms.
The starter solenoid is about .34 ohms. Or a total of 0.53 ohms, or around 22 amps at 12 volts.
Those numbers don't exactly work out, I was seeing a bit under 7 volts at the solenoid and 22 amps should be a bit over. But it is in the ballpark when you add on battery resistance etc.
The red/whte wire from the main 30 amp fuse passes by the starter relay. I tapped into that, cut the yellow wire from the 15 amp fuse, and tied the strong positive straight to the relay. That gives just under 10 volts at the solenoid, or about 30 amps instead of the 22. At 30 amps the wire from the relay to the solenoid is dropping 0.88 volts. I can't believe the starter solenoid needs that much more to energize, so I didn't touch that.
Hopefully that nearly 40% increase in amperage will make a world of difference.
sign216 said:Patrick Hayes suggests an easlier solution:
So what do you do with the red/yellow wire that you pull out of pin 5, just tape it off?
Tape, or a crimp dead-end cover. Whatever you prefer just to be sure it doesn't short to ground.
Here's a little graphic that should explain the improvement.
Look inside the relay diagram which is item #36. That little "P" shaped circuit on the right, fed by pins 1 and 2, is the relay's internal operating electromagnet coil. Not much work there.
Now look at the 'bridge' connection circuit fed by pins 3 an 5. When the electromagnet is energized, it pulls that "T" shaped device against the two internal connectors and bridges or 'makes' the connection. Pin 3 now feeds electrons out to your starter solenoid. The electrons come in via pin 5. But, that pin 5 source does several other things as well and has to pass through numerous connector blocks before getting here. We loose a little bit of power at every connector. Eventually, even though we still supply 12 volts to the solenoid, we no longer provide enough amperage to actually throw the heavy electromagnet in the solenoid. Thus, all we get is the 'click' of the relay itself.
If we simply provide a direct circuit from the battery into pin 5, we haven't changed anything about the operation of the relay, only the source of electrons which we will feed to the solenoid.
baloches said:after a good wait the battery would recover enough power to overcome the ECU's low-volt threshold and the bike would fire right up.