BXpanded
Silver Member, Approved Advertiser
My guess is that the 6 volt test is simply a test to see if the solenoid will work when the battery is partially discharged. I'm sure it is intended to operate at 12 volts.
Re the 6 volts to test solenoid;
could it be that they are actually using a 6 volt solinoid due to voltage drop when the starter in engaged?
starters will often drop line voltage to 8 volts or so, and a 12 volt solenoid would risk opening under low voltage condition.