I am replacing capacitor on central a/c unit. I have two brown wires and one red wire to reconnect. What wire goes to what post on the replacement capacitor?

on the motor should be a diagram detailing the wires. brown white goes to either side of the capacitor and brown wire to other side of capacitor. hi speed goes to normally open contact on the indoor fan relay and the wire designated common on the motor goes to the other side of power from the relay contacts.

It sounds like you'll probably need a capacitor .......

that is a dual capacitor, common goes in the middle, compressor goes to herm, fan goes to fan. let me know.

you need to replace the cap, there is no low speed, the capacitor is bad

The brown wire goes to the capacitor. It probably shorted out with the nicked wire. Replace the capacitor.

on 120v units most likely will be white should be common,black should be hot,brown to capacitor, and green to ground transformer sounds to be wired correctly.

2 brown wires go to a split capacitor if you have a dual cap which has three terminals marked comp fan com if u have this type of capacitor then the brown wire goes to fan and the brown and white gets capped with a wire nut. whenever replacing a fan motor you should also replace the cap or at least check the capacitance to see if it is still good. you have to check it with a meter that test microfarad.you can get a permanent split capacitor and mount it in there then u use the brown on one side and the brown and white on the other side it only has 2 terminals.

I think this is a double problem post,so I will answer the top first.
The fan capacitor may be bad or the motor it's self is seizing up and will need replaced.

Second portion of post:

1. Brown and brown/white go to the new capacitor(If you didn't get a new one with the motor,You will need to)Should be 7.5 mfd
2. Black To the contactor where the black was originally connected
3. yellow to the contactor where the red was originally connected

Motor Wiring
Old Motor
Brown wire is Start
Yellow wire is run or Power
Black wire is High Speed or Common
The other two taps are speed taps, but you have a single speed application
And high speed is what you need ,that’s why there’s not any wires
on Red and Blue if high speed was to much then you would move the
Black wire to one of the other taps RED low speed or Blue Medinm speed
New Motor
White goes to the Yellow wire from the capacitor
Black goes to the Black wire you took off of high speed on old motor
Of course both Brown wires go to the capacitor and Green to ground
If a capacitor doesn’t discharge it doesn’t mean it’s bad
but the capacitors don’t last as long as they used.
Any time you put in a new motor always replace the capacitor
It will save you a lot of time and grief later on.

EMERSON 1/4 HP MOTOR 5 WIRES BLACK BLUE BROWN WHITE RED LOST MY DIAGRAM 115V1075 RPM 3 SPD HOW DO I WIRE IT TO THE COMPRESSOR