This US locomotive consists of two drive units (FA1 and FB1) each with two motors. They are opened from below via a multitude of screws along the housing edge. Here is the FA1 after opening:

ALCO FA1 open

… and the FB1:

ALCO FB1 open

In both models, the previous owner obviously made modifications, having carried out a digital conversion on the FA1. After spending some time trying to understand the wiring, I decided to rewire it.

Since US locomotives in scale-G are known for their high power consumption, I decided to use the CTC-Locmodule-G in the version with 6 A peak (No. P2-05-05). Each of the two locomotives will receive its own locmodule so that each of the four motors will get its own motor output. The two locomotives will later be coupled via the CTC app.

I have temporarily disconnected the smoke generators and postponed their activation for later.

Here is the wiring of the FA1:

ALCO FA1 Modification-1

ALCO FA1 Modification-2

And the wiring of the FB1:

ALCO FB1 Modification-1

ALCO FB1 Modification-2

TODO: Images and text for NFC-Reader