trim problems 1979 merc 470/#1

[bob weaver]

1979 merc 470 w/ #1(i guess) outdrive<br /><br />just bought the boat a week ago, and knew there was a frozen trim cylinder on the port side, but the starboard worked fine. now neither are working, and i can't hear the pump running. could the pump have been damaged (seals or something) by working it on one cylinder while the other was frozen (outdrive was not attached at the time of testing)? could it be a relay? i'm pretty good with cars, but this is my first boat and the whole outdrive dealie is foreign to me (i did get it "pressure tested" before purchasing and it was fine). the only thing i know it's not is the fuse. please advise, or just give me a lowdown on the trim system and i'll try to figure it out.<br /><br />in dire need of a manual. there seem to be two popular ones, clymer and seloc. which is better, or are there other options? <br /><br />thanks for the help, look forward to learning and returning the favor.