1970's Mercury Power Trim Problem

SEMOdave

Recruit
Joined
Jan 20, 2019
Messages
2
I have a 1972 Mercury 50hp 500 series Thunderbolt outboard. For some reason when I hook the wires for the trim up to the battery the pump turns on and runs the motor up. Can anyone tell me what is causing this??
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
39,261
?----When did the problem start ?----New battery installed ?-----Wiring changed ?---------Without being there I would say the solenoid is jammed.
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Sounds like you have mistakenly made the other side of the relay/solonoid live permanently to the battery...or the relay/solonoid has shorted.
 

SEMOdave

Recruit
Joined
Jan 20, 2019
Messages
2
I finally found the problem! I had put a new battery in but turns out the wiring going through the side of the boat up to the switch had fried. someone before me had spliced the wires and did a terrible job. when the coatings melted off the blue wire was touching the power wire. I had ran new wires to the down limit switch but it had been by-passed in this splice so once i hooked it back up the motor would turn on if the switch was closed. Thanks for the responses guys!
 
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