https://www.americanzline.com/docs/AZL-Truck-Installation-E8-E9.pdf These same instructions apply to F units. For the tail A unit, you have to take the shell off, remove the pilot, and replace the front truck with the extra truck with a truck mounted coupler that should be provided under the package insert. The Alco PAs are the only exception. The front truck needs a longer front coupler with the long nose overhang that isn’t included with locomotive. This coupler can be obtained from ztrackcenter.com as AZL part number 9900X-PA “Alco PA1 extended coupler.” Because of the way model trains are designed, with electric polarity separate for each rail, it doesn’t matter if the engine is facing forward or backward on DC power if that is what you are asking. They will all go the same direction when power is applied. Rotating the engine does not reverse its direction on DC power. -Matt
The Main concern with ABBA consist is the total current draw of the consist and can your throttle handle that current without tripping the breaker. Other than that put a pair of them on the track and put the power to them, if that works the try 3 if that works then try with the 4th. The newer locos today tend to run 125 - 150 MA running light and up to 200 Ma loaded, so you need a throttle that can deliver at least 1 amp at 9vdc to reliably run an ABBA set, on DC. There is one loco That will probably over load your controller at 1 amp and that is the MTL F7in an ABBA set.
