I put my Pertronx plus new coil. It works beautifully.
Now I carry the original coil as spare. It is marked + and -- for plus grounded situations.
Do I have to change poles when using it for minus grounded?
I was not able to determine the current ways by measuring Ohms:
minus to plus has only 2,5 Ohms, DistOut to + has more than 1 K ohm, so measuring DistOut to minus
shows only a not noticable difference.
The Coils are not marked if for plus or minus grounded systems.
Thanks! Go
Go:
If the system is - ground, then the - terminal on the coil goes to the points, and on to ground. If the system is + ground, then just reverse the terminals on the coil. A coil is not polarity sensitive, but the spark plugs are, and if the coil polarity is reversed then the spark will go from the plug shell to the centre electrode rather than from the electrode to ground. You probably won't notice any difference in performance in terms of the engine, but the plug life will be shortened.
Brian
Thank You, Brian.
Am I right that coils never are specified if plus or minus grounded?
all mine are not.
Greetings! Go
Hi Go:
As far as I know all coils are just marked with + & - terminals and the installer simply grounds the correct terminal to correspond with the battery terminal that is grounded. In my experience, any 6 volt coil will work with any 6 volt system - early Ford excepted. In terms of 12V systems, some coils require a resistor in series that is bypassed while the starter is engaged and then drops the voltage to the coil to about 9 volts when the engine starts.
Brian