I am replacing my 3 wire condenser fan with a universal that has 4 wires
1 black
1 white
1 brn/white stripe
1 brn

I bought a new dual capacitor at the same time so my question is where do the 2 brown wires go on the dual cap? The old one had one brown wire.

The two brown wires go to the NEW capacitor you bought to go with the new motor.

The black and white go to the load side of the contactor. One wire to each side of the 220/240 volt contactor. The old capacitor will no longer be used for the new condenser fan motor but it will still be used as the run capacitor for the compressor. When the inside unit/thermostat activate the unit outside the contactor will pull in sending 220/240 volts to the new condenser fan motor so it operates. See attached doc.

REMEMBER to also hook up the green wire to a good ground or you could hot up that unit if the motor ever faults.

Thanks for the reply, the new cap is a dual like the old one only it has a different rating for the fan so I put the brn with white stripe to the common and the solid brn to the fan side and the blue wire from the compressor went to the herm marking. White went to one side of the contactor and the black wire went to a pcb board then to the contacor. I forgot to mention that my unit is a heat pump. Cranked it up and it seems to be working better then ever as it cycled 3 times in the last hour.

Glad you got it running.

I think that is wron. The solid brown should have been put on the capacitor terminal while the shaded wire is caped off.