On a 1033, the common post is the A post and the "hot" side is the U post. BUT...if you intend only to use the 1033 for the switch motors, and not for any other track-associated loads, then it doesn't matter which post, A or U, you assign as the common.
(The letter designations on transformers are sort of ambiguous, and arbitrary. They vary, as you have seen, from one model to another. Lionel didn't really have a logical system. The designations are put there to allow a kid to hook up his trains to a single transformer without a lot of head scratching. Remember that in talking about outputs from A-C toy train transformers, there is no "hot" or "ground" or "return" until the user assigns those designations by actually fastening wires and devices to the posts. One man's hot is another man's return.)
Here's the procedure:
Connect the U from your KW to the U from your 1033. Plug them both in, and set their outputs at the same voltage, using a voltmeter.
Using your voltmeter, take one test lead and touch it to the A post on the KW, and the other test lead and touch the A post on the 1033.
You are looking for a reading close to zero volts, if the transformers are in phase.
If you get a reading that is close to the sum of the individual output voltages, they are not in phase.
If that is the result, reverse the line cord of one transformer, and then mark the plugs so that you will always plug them in the same way in the future.
