Br143 Tap Changer

I'm sure I've asked this before, but I simply can't find the thread and I can't remember what was said. How do you use the tap changer manually in the BR143? I remember doing it before but I can't remember how I did it.

 

Set the AFB lever to on, then use the auxiliary control switch to manually raise or lower the taps

 

Not sure, but I may have described in the Ruhr-Sieg Nord route guide. To be honest< I never do that.
You can get the guide here: https://www.hollandhiking.nl/trainsimulator