Mopar Electronic Pickup Polarity and Rotor Phase
Unless the dist is improperly manufactured, or modified, or wrong parts, a breaker points dist, the mechanical advance and rotor phasing will always be correct because as the trigger device (points) are moved mechanically by the advance, the rotor is always still kept in the same relationship to the points cam. The cam/ rotor cannot move in relation to each other.
HOWEVER the vacuum advance is a different story. The vacuum advance moves the trigger point by moving the points on the breaker plate, BUT THE ROTOR has not been moved accordingly. So vacuum advance depends on the width of the rotor to stay properly aligned. This explains why, if you find certain 4 whanger and 6, mostly V6 rotors, they sometimes have odd, wide shaped rotors
So when you swap polarity on a magnetic pickup, the trigger wave is moved, just like when the vacuum advance moves the points, only in the case of breakerless, it moves far enough that the rotor can now be clear out of alignment with the plug tower contact when the trigger fires the spark
On a side note, some of these foreign rigs with the black stuff there is a radio suppression resistor, and I was tricked once on a dead Toyota where that burned up. After finally figuring it out, and no spare, we jerry rigged a piece of wire to jump across to get home.
Let's try this. Think of a points dist.
Unless the dist is improperly manufactured, or modified, or wrong parts, a breaker points dist, the mechanical advance and rotor phasing will always be correct because as the trigger device (points) are moved mechanically by the advance, the rotor is always still kept in the same relationship to the points cam. The cam/ rotor cannot move in relation to each other.
HOWEVER the vacuum advance is a different story. The vacuum advance moves the trigger point by moving the points on the breaker plate, BUT THE ROTOR has not been moved accordingly. So vacuum advance depends on the width of the rotor to stay properly aligned. This explains why, if you find certain 4 whanger and 6, mostly V6 rotors, they sometimes have odd, wide shaped rotors
So when you swap polarity on a magnetic pickup, the trigger wave is moved, just like when the vacuum advance moves the points, only in the case of breakerless, it moves far enough that the rotor can now be clear out of alignment with the plug tower contact when the trigger fires the spark
On a side note, some of these foreign rigs with the black stuff there is a radio suppression resistor, and I was tricked once on a dead Toyota where that burned up. After finally figuring it out, and no spare, we jerry rigged a piece of wire to jump across to get home.