Trim will not go down

[Zoller]

I have a 1981? Javalin 85hp. Trim will not go down without help. Trip moter runs and sounds good. Was told possible plugged valve. I have unit on work bench. I hook green (maroon)wire to neg. and black to pos. to go up and black to neg. and dark green to pos. to go down. What am I looking for or am I hooking it up to the jumper box wrong?

 

[GA_Boater]

Welcome aboard.

This is a Johnson, isn't it? Moving it to the J-E section because it is a repair question.