trim pump-solenoid?

let me preface this by saying that i have never done any work on an outdrive/trim system, being as this is my first boat. okay, the trim pump worked when i was there with the owner checking out the boat, and now it does not. there is no noise at all when i trim up or in, but when i press up and up/out at the same time i get a click coming from what i assume is the solenoid. connections are all fine, i get the same click when i connect the blue (up) lead to the battery+. yes, it is in forward gear. the repair manual makes no mention of this click. can i bypass the solenoid to determine if it is the culprit? how so? what else could it be? i'd like to get this tackled and then move on to replacing the impeller and gear oil in the outdrive. i'm going bow to stern, you see (i know engines well enough, no problems yet), and i don't wish to get ahead of myself. help would be appreciated :).

[chumbucket]

You're on the right track. It's most likely the solenoid. You didn't mention what brand outdrive you have but I'm assuming it's a Mercruiser. Most Merc's utilized a Prestolite trim pump system and have two solenoids. One for the raise circuit and one for the lowering circuit. There are ways of checking with a multimeter but the simplest method is to short circuit the solenoid. the two large posts are where the current passes through to energize the coil which will allow for the voltage to flow to the raising (or lowering) circuit. So, the easiest test is to jump the two posts and it should allow the outdrive to raise. the solenoids are a very common item and not very expensive (thankfully unlike everything else with boats). The Prestolite motors and pumps are very reliable and last a long time.

thanks for the help :). sorry i didn't stipulate originally that it is a '79 470. i don't think it's the prestolite, there's only one solenoid attached to the motor, but i'll try jumping it today and get back to you on the results.

[chumbucket]

Yeah, some of the older ones only used one solenoid. It may not say Prestolite, but I'd bet it is made by them. ;)

[macojoe]

I love I/O !! NOT!