How to connect a three-phase motor
If it is really a three-phase motor then the following applies.



Figure 1. Top: three-phase motor windings connected in star (Europe) or wye (North America) configuration. Bottom: delta (\$ \Delta \$) configuration. Source: Electronic Project Focus.

You should get the same resistance reading between L1 - L2, L2 - L3 and L3 - L1.



Three wires does not mean three phases. For example, it could be a single-phase motor with live (L), neutral (N) and earth (E).

Photos and a geographical location would help. (That's why it's an option in your user profile.)