1983 75HP Johnson tilt/trim motor

kevdog2000

Cadet
Joined
May 20, 2012
Messages
24
Hi all, my tilt/trim motor doesn't work all the time. I think the motor is bad because if I tap it with a hammer it'll start working. However, for my question, when testing the voltage I noticed that I get 12V on the blue and green wires regardless of whether I'm pushing the up or down button. The motor works correctly, meaning when I push up it goes up and vice versa. It's a 3 wire motor, blue(up), green(down) and black(ground). I'm curious if this is correct or I have an issue in the wiring.

Thanks for your help!

Kevin

1983 75hp Johnson Sea Drive
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Something does not sound correct. Are you sure of the year of the engine? Was the powerhead changed ever? That 1983 engine came from the factory with a 2-wire trim motor, not a 3-wire. The last 3-wire trim systems were made up through midway through the 1981 model year. The 3-wire system takes a different electrical control box from the 2-wire motor. Are you working with matched parts here? If the motor and the control box were changed as a matching set, it should work ok. Either system is a good system, just be sure the parts match. (The control box for the 3-wire motor uses a single solenoid in the box, the 2-wire motor uses a pair of matched relays.)
 

kevdog2000

Cadet
Joined
May 20, 2012
Messages
24
Thanks for the response...you are correct about a change...the previous owner put a 1983 Johnson J75TLCTE motor on a 1979 85TL79R transom mount. I wasn't sure whether to use the motor or the transom mount number in my post. It is a 3-wire trim motor and the control box has a single solenoid for the blue wire and a relay for the green wire. I still am trying to determine whether I should see voltage on both wires when I try to raise or lower the motor. Logic, to me, says that I should only see 12V on the blue wire, 0V on the green wire, when I raise the motor and 12V on the green wire, 0V on the blue wire when I lower the motor. I don't know if having 12V on both wires when raising and lower the motor is correct.

Thanks again!
 
Joined
Feb 17, 2012
Messages
2,906
unplug the motor then test the voltage. With the motor plugged in if blue has 12v you will be able to read 12v on the green as its linked inside the motor. If you get 12 on the blue and green when the motor is unplugged then you have a problem in the wiring.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Ah, that sounds correct. The 3 wire is a good system. The blue should be powered when the trim is going back, the green when the trim is being tucked in. The solenoid is in the circuit when it's going back (up) only. When trimming down, all the power goes thru the down side of the control box handle trim switch. The trim relay box originally came with a trim wiring diagram pasted inside the lid of the box. Make sure all your wires are solidly attached and not frayed. If some wires are missing any strands, it will act up.
 
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