02-01-2019, 03:34 PM
Yes, doc, I’ve no argument with the process you’re following. As usual, it’s logical and methodical.
Is this the bit of the article you wanted?
from http://xlforum.net/forums/showthread.php?t=1896417 Wrote:When the starter button is pressed (key on, off/run switch in run mode), voltage is sent to the coil of the starter solenoid. If the system voltage is normal, the starter engages.
If the system voltage is low, due to low battery or faulty battery cables (the frame/motor end of the negative cable is a common issue), then the voltage may be sufficient to close the coil, but when it closes the high amperage contacts from the battery to the starter, the low voltage has a compound effect:
1. Lower voltage is a challenge to the starter turning over the motor and
2. Lower voltage results in a higher amp draw for the motor to try to pull the same wattage.
For example, a 1.4 KW starter draws 109 amps at 12.8 volts, 111 amps at 12.6 volts , 113 at 12.4 volts, 133 at 10.5 volts, etc.
In a low voltage condition, once the starter tries to draw enough amps to turn over the motor, the voltage drop is so excessive that the coil cannot remain energized and it opens the high amperage contacts to the starter. If the starter button is held, the voltage recovers (after the coil drops out) enough for the coil to again close and the cycle repeats until the voltage drop will not allow the coil to close. This is solenoid chattering.
Is this the bit of the article you wanted?
from http://xlforum.net/forums/showthread.php?t=1896417 Wrote:When the starter button is pressed (key on, off/run switch in run mode), voltage is sent to the coil of the starter solenoid. If the system voltage is normal, the starter engages.
If the system voltage is low, due to low battery or faulty battery cables (the frame/motor end of the negative cable is a common issue), then the voltage may be sufficient to close the coil, but when it closes the high amperage contacts from the battery to the starter, the low voltage has a compound effect:
1. Lower voltage is a challenge to the starter turning over the motor and
2. Lower voltage results in a higher amp draw for the motor to try to pull the same wattage.
For example, a 1.4 KW starter draws 109 amps at 12.8 volts, 111 amps at 12.6 volts , 113 at 12.4 volts, 133 at 10.5 volts, etc.
In a low voltage condition, once the starter tries to draw enough amps to turn over the motor, the voltage drop is so excessive that the coil cannot remain energized and it opens the high amperage contacts to the starter. If the starter button is held, the voltage recovers (after the coil drops out) enough for the coil to again close and the cycle repeats until the voltage drop will not allow the coil to close. This is solenoid chattering.