Power trim solenoids

SdupontJr

Recruit
Joined
Oct 27, 2013
Messages
1
First off guys, great site with lots of helpful info and knowledgable folks. I have a older 3 wire mercury power trim motor 17649A1. This trim and resevoir is used on my Pro-Drive outboard motor for shallow water hunting. The way that its wired is that they use a warn winch switch and all the current is passed through the switch. Not a good design in my books. I have owned several merc outboards (150, 200, 225) and they use solenoids, basically acting as a relay to protect the switch so I presume. I would like to add this feature to my merc power trim unit. The rest is hydraulics and thats working fine. My question is what solenoids would I need with this 3 wire motor (mercury 17649A1)? I know I need two, but not sure which ones.

Also, because it is not wired through a mercury wire harness, some of the wire drawings won't work. I currently have changed out the winch switch (was acting up, probably due to amp draw across switch) to a SPDT 25 amp mom on-off-mom on waterproof switch. This is what I would like to use to power the solenoids. Thanks for any help and great website.
 

RRitt

Captain
Joined
Mar 30, 2006
Messages
3,319
Re: Power trim solenoids

my advice would be to use a generic 2w trim harness with in line fuse. They are available for about $30.

Relays have replaced solenoids in trim wiring for good reason. They offer an inexpensive, reliable, easy to install, easy to service, universal wiring scheme for all 12v reversible motors in automotive or marine use. Boat people automatically assume that relays are only for 2w motors. Not true. The same relay harness can be used for either 2w or 3w without any modifications. All that is required is a different relay. use 5pin relays for 2w motors and use 4pin relays for 3w trim motors.

You can also make a 4pin Normally Open relay from a 5pin Normally Closed relay by simply breaking off pin #87a. Pin # 87a is the exact center pin.
 
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