Since the unit is out of the machine I'm assuming you have nothing connected to U,V,W which should be the case when doing this check.
Put a meter lead ont he DC bus and then the other one to U then V then W. They should all read the same resistance (or close) You can also check this on the diode setting of your meter.
Then move your lead from the motor terminals to the the terminals on the top of your contactor and check those readings. They should be the same also.
If you're getting increasing resistance then you need to reverse your leads.
After checking those 6 terminals, move your lead to the other rail of the DC bus and do the same test. You will have to reverse your leads when going from the positive to the negative bus or vice versa.