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Hi have decided to pull the radiator exhaust oil pan rocker cover carbs manifolds and do a final push to get the bike finished .i am about to remove the coils and have noticed the resistor has been taken off and the three separate coil wires are joined to the the yellow wire when i brought the bike it said they have fitted cb900 coils if this is a correct fix i just want to check the polarity of them can someone please tell me are they to go to the negative or positive side of the coils i know it will run fine either way Ive found that many faults with this bike every time i work on it something needs repairing its always had a slight miss just on take off and a rough idle just found right hand carb throttle plate backed off so no idle on that carb and left hand card adjuster loose all the thinks that were supposed to have been done thanks Graham

The stock "ballast resistor" is often removed if the replacement coils resistance are already in the correct range.

The 1979 KZ1300 has basic transistor ignition, the igniter can handle primary resistance of coils that is between 2.5 and 4.0 ohms. You can easily measure the resistance from the low voltage terminals of the coils, just set your multimeter to correct range and touch the terminals.
The polarity of the coils is sometimes marked near the low voltage terminals with + and -
The yellow wire brings +12 V to the coil + terminal, the blue green or black is the trigger wire to ignition coil -, timing the spark release.

thanks for the help ill measure the coil resistance this weekend