Hello Charles!
How are you?

Let me know if I understood correctly... You want to know how to run the locomotive backwards inside the garage, after turned it 180 grad in the turntable?

Since you said you are working with 50/70's stuff, you need to switch the locomotive relay to run in reverse, i.e., turn the control knob to 'below zero' just a few seconds to 'click' the relay; after that just run the locomotive backwards.
After that, you should 'click' again to exchange to the forward run position.

Also, maybe your locomotive also have a lever on the sides to manually exchange the relay.

Cheers,

Walter

Charles:
A little more clarification of the above. Drive the locomotive onto the 7186 turntable and bring it to a stop. Rotate the turntable until the locomotive is facing away from the track leading to the shed/track that you want to store it on. Activate the reverser using the control as mentioned above. Slowly reverse until the locomotive reaches the point that you want it to stop at. Make sure that your shed/storage track has it's power isolated so that the locomotives don't move when you are operating other ones.

Regards

Mike C