positive ground coil + vs -

[offy19]

on a 6V positive ground system do you attach the hot lead (negative battery) to the + or - side of the coil and why?

 

[alanwoodieman]

attach to negative side, otherwise your coil will overheat, also because of polarity, you know neg to neg, pos to pos

 

[offy19]

Thanks Allan

 

[supereal]

Attach as set out above. It is important due to the construction of the coil which joins the windings at the input post. The primary winding goes to the points and condenser to find ground, while the secondary winding feeds the high voltage to the distributor rotor.

 

[slowforty]

With the car running.
Carefully pull a plug wire.
Place a pencil between the end of the wire and the spark plug.
Spark should go toward the pencil to the sparkplug.

If the spark goes from the sparkplug to the pencil, reverse the wires at the coil.
Car will start easier if coil wires are correctly terminated.

 

[Jack E/NJ]

>>>Spark should go toward the pencil to the sparkplug. If the spark goes from the sparkplug to the pencil>>>

Sparks go pretty fast. How can you tell which way they're going?

Jack E/NJ

 

[rotorwrench]

They used to make it easy back in the day. The coil had Dist and Bat terminal markings but the later coils with + & - leave a bit to be desired. You can still buy the little polarity checkers like this: http://www.macsautoparts.com/ford_mercury_early/ignition-and-coil-polarity-tester-kit-1.html

 

[zzlegend]

I use a polarity checker like rotorwrench shows. I use it every time I change a coil and just in case the markings on the coil are wrong.

 

[Ronnie]

Here u go
http://mgaguru.com/mgtech/ignition/ig104.htm

R

 

[Jack E/NJ]

Thanx Ronnie. I vaguely recall that article. I guess the so-called 'flare' position depends on graphite particles being knocked off the pencil and ignited in air by the direction of the electron beam.

Jack E/NJ

PS I think I'll continue to use a meter 8^)

 

[El Rat]

The easy way to remember is: It's exactly backward from what you learned. That is if you are 65 and younger cause nothing back then (post 1955) was + ground!