mercury tilt trim goes up not down

[1990merc 50]

tilt trim only goes up unless i switch motor wires to use up for down

 

[R_P]

Is this on a remote? For me it was the little wires in the remote handle that broke.
First step is to continuity test the switch

 

[Droid]

Does that 1990 have a switch on the engine too? If so, does it work normal from there?
2 relays in system? Swap relays around & see if problem reverses.