Wiring Question - Trim pump unit seems bad 2007 5.7 SX-A

[Tydog96]

Part number 21945915. Pulled unit (mounted outside transom) based on initial troubleshooting. Lots of rust, some water, etc. Direct connect 12v power to the trim motor is unresponsive. WIRING: The power feed is two heavy gauge wires (Blue and Green). I get power there when tilt button rocker is activated, but still confused at UP versus DOWN. I thought maybe they are both POSITIVE coming from relays (up or down related) and thought the ground was maybe the cable wire to the bolts. But if I hook just a normal 12v tester, that is not what I see. How do I test. Confidence is high motor bad. I see power to the main wires, but don't how to proper test, and UP versus DOWN function. Again, looking to test wires to verify overall wiring works as designed. Thanks

 

[dingbat]

Part number 21945915. Pulled unit (mounted outside transom) based on initial troubleshooting. Lots of rust, some water, etc. Direct connect 12v power to the trim motor is unresponsive. WIRING: The power feed is two heavy gauge wires (Blue and Green). I get power there when tilt button rocker is activated, but still confused at UP versus DOWN. I thought maybe they are both POSITIVE coming from relays (up or down related) and thought the ground was maybe the cable wire to the bolts. But if I hook just a normal 12v tester, that is not what I see. How do I test. Confidence is high motor bad. I see power to the main wires, but don't how to proper test, and UP versus DOWN function. Again, looking to test wires to verify overall wiring works as designed. Thanks

You reverse a dc motor by switching polarity.
Y = Blue (+) Green (-)
Z = Blue (-) Green (+)

 

[ESGWheel]

Here is a site (link) that explains how these systems work electrically plus some troubleshooting tips.