1996 evinrude

[keakar]

don't overlook any tilt pin bushings if you have them and grease the pivot pins. they can get sticky when dry. in most cases trimming down brings the pin in and the motor comes down by its own weight and your motor tilt pins may be getting stuck. when trimming up it is under ram force so its a lot less likely any tightness in the tilt pivot pins will be noticed.

as mentioned the ground comes through the wires so you are good there.

also whenever you have trim issues if trim up is the problem then check the trim down relay and if trim down is the problem then check the trim up relay

try switching the relays to be sure they aren't the problem, if it were air in the system it would settle itself out naturally after several up and down cycles and not be an ongoing issue. provided it has the correct amount and type of fluid in it.