my coil is hot on the possitive and negative sides with the key on. WHY????? i have the distributor condenser wire hooked to the negative side of the coil and the wire from the ignition swith to the possitive side like i thought it should be but why do i have both hot with the key on?
It's a complete circuit - you're just measuring the voltage before & after the primary side of the coil. Even if you disconnected the wire going to the distributor & measured the voltage at the "-" terminal of the coil, it would read 12V (the meter completes the circuit).
If you didn't have voltage at both terminals, the coil would be defective. You will have voltage all the way down into the dizzy up to one side of the points. Current only flows when the points are closed completing the circuit. When the points open breaking the circuit, the coil discharges through the "secondary wire" (coil wire) to the dizzy cap and on to the plugs. As soon as the points make contact again current flows recharging the coil again. The coil fires again when the points open again and again and again. The primary wire.. the small wire that you are testing is a continuous wire that is wrapped around inside the coil with, but not touching, the secondary windings. Like any hot wire, you will get voltage any where along that wire. You don't have a problem.
Actually the condenser/capacitor is what charges and "collapses" when the points open causing the coil to fire the high voltage low amp spark. If you aren't getting spark, it could be the condenser, coil, or the wiring going between them or the wiring going to the points broken or grounded. Check it for voltage flow with a "dead time" test light like you would on a VW, not a volt meter. Light should come on when the points open, otherwise it's still going to ground somewhere else between the coil and distributor.
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