Early heater motor

[970s]

Hi, does anyone had the experience to change the motor's rotation direction by switching over the positive and negative terminals from battery ? I found my mk1 fan motor (with two white leads ) , turns to only one direction (wrong direction as indicated by the arrows on the fan vane) whatever I connect it to negative earth or positive earth setup! Can I change the motor's field by short circuit it like the dynamo?

Al

[Spider]

Sounds like it has wound field coils instead of permanent magnets. If so, then you need to swap over either the field wires or the armature (brush) wires to change it's direction. Swapping both (as in the input wires as you've done) won't do it. I'm not sure I am familiar with your particular fan motor, but some can be turned end for end to reverse the rotation.