Is there a preferred polarity?

[john108]

Windshield washer Pump.
The picture shows 2 spade type connectors.
I tested the pump with water in the tank.
I had one terminal "+ "  and the other "-".
Then I reversed the Polarity.
The flow appeared the same in both tests.
I only took the voltage to 9 volts.

Is there a preferred polarity?
Thank You,
John

[John_Kunkel]

Some pump rotor designs aren't sensitive to direction of rotation, they'll pump about the same in either direction.

[b5blue]

Should be in the FSM. 

[birdsandbees]

Should be in the FSM. 

A factory pump only has one spade for the +.

Pump should turn in the direction of the outlet spout, in this case CCW looking at the pump end. How you're going to visually see that, I don't know..

[john108]

Thankyou for the replies.
I am guessing that the rotor has flat blade(s) and may not care which way it turns.
The flow was strong in both directions (polarities).
I didn't try to measure pressure.
I am going to go under the assumption that it doesn't matter.
Thank You,
John