Please take a look at this transformer. It was on a power supply board with the following information.

115V 60Hz 0.4A
Out
+5V 2.0 A
+12V 0.7A
-12V 0.3A
Which two output wires (A to F) should I use, if I want to get 12V AC with at least 2A out of this transformer ? (I don't need DC voltage)

 

First measure which windings are connected or common resistance test, next simply power the primary and measure the AC outputs that had continuity between them.
Max.

 

First measure which windings are connected or common resistance test, next simply power the primary and measure the AC outputs that had continuity between them.
Max.

I don't see a possibility of getting 12 V at 2 Amps out of that.

 

I can't get +12V at 2 amps out of this transformer, since it is rated at +12V @0.7A. The wattage of the xformer right now is 22 watts - you want 24 watts. You will need a bigger transformer.

 

Thanx Max,
I measured
A-B 29.4V
A-C 14 V
E-F 12.6 V
Is there a way to be sure which is going to give me 2 Amps ?

 

Going by the apparent wire gauge, the size of the bridge rect and the large caps, I would say you should be plenty OK with 2a.
The transformer looks capable of 50va.
Max.

 

Thanx Max,
I measured
A-B 29.4V
A-C 14 V
E-F 12.6 V
Is there a way to be sure which is going to give me 2 Amps ?

Use it and see if the magic smoke escapes..........................................

One of the wire pairs looks to be bifilar wound - that winding is the highest current.