Help with tailgate lift motor

[firemedicsafd]

Im getting power from the switch on the dash both ways to the connectors at the base of the tailgate. I get signal on each side at the motor connector but one is WAY dimmer than the other using an LED test light. The motor, hooked direct to a battery and out of the tailgate, runs both ways equally fast. BUT hooked back into its designed location it won't go down. Only up. Grounds appear to be good. PLEASE help! DO i need to spring for a new motor or switch the connectors to something that will conduct more electricity? Thank you for your help!

ALSO, the exterior key will not operate the unit at all.

 

[dyeager535]

If the connector shows different "voltage" (I'd use a voltmeter, not a light) disconnected from the motor, then it stands to reason the motor isn't the sole issue, if an issue at all.

I'd want to check resistance on both the wires to see if one was worse than the other, and if so, resolve that issue.