1991 mariner 75 hp tilt and trim occasionally working

cmarbles

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Dec 22, 2013
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Hello all,
I'm not very boat knowledgeable so I don't know where to begin but here's my problem, I have 1991 75 hp mariner(3ram system) and the tilt and trim occasionally works some days no issues and others it wont move at all and when it does move the lower it gets the slower it gets, I have checked the fluid and added to it and that helped WHEN it decided it wanted to move,the battery is fully charged also.....any suggestions?
 

alldodge

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Re: 1991 mariner 75 hp tilt and trim occasionally working

:welcome: to iboats

The number one issue with most all electrical problems is corrosion. Start by checking connections, pull plugs and connectors apart and verify they are clean, clean the ones which need it. Does the motor run but no movement or the motor does not run when button is pressed?
 

cmarbles

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Dec 22, 2013
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Re: 1991 mariner 75 hp tilt and trim occasionally working

:welcome: to iboats

The number one issue with most all electrical problems is corrosion. Start by checking connections, pull plugs and connectors apart and verify they are clean, clean the ones which need it. Does the motor run but no movement or the motor does not run when button is pressed?
Thanks for the response

I checked connections and they are all fine.. I can hear it click when I press the button in either direction but the motor doesn't engage all the time.. Sometimes it will and sometimes it won't,as of now it will not.
 

RRitt

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Mar 30, 2006
Messages
3,319
Re: 1991 mariner 75 hp tilt and trim occasionally working

Hello all,
I'm not very boat knowledgeable so I don't know where to begin but here's my problem, I have 1991 75 hp mariner(3ram system) and the tilt and trim occasionally works some days no issues and others it wont move at all and when it does move the lower it gets the slower it gets, I have checked the fluid and added to it and that helped WHEN it decided it wanted to move,the battery is fully charged also.....any suggestions?

get a known good 12V auto. marine, atv, or lawn battery and hotwire the trim system. if it operates properly then focus your repair efforts on wiring, solenoids, and switches. If it does not operate smoothly when hot wired then it is probably a bad motor. Motors are not worth the effort or risk of repairing. Just replace it.
 

cmarbles

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Dec 22, 2013
Messages
5
Re: 1991 mariner 75 hp tilt and trim occasionally working

get a known good 12V auto. marine, atv, or lawn battery and hotwire the trim system. if it operates properly then focus your repair efforts on wiring, solenoids, and switches. If it does not operate smoothly when hot wired then it is probably a bad motor. Motors are not worth the effort or risk of repairing. Just replace it.

how do I go about hot wiring the system?
 

alldodge

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Re: 1991 mariner 75 hp tilt and trim occasionally working

how do I go about hot wiring the system?

If you go back to the link I posted in number 4 it has a wiring diagram of the different systems. Find yours and see how it is wired. You can jumper across right to the solenoids or motor, or use the trouble shooting guides to find the issue. To jumper motor only find the Blue, Green and Black wires coming from the motor. Connect ground to the black and green to the positive for one direction, and then connect the positive to the Blue for the other direction.
 

RRitt

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Mar 30, 2006
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3,319
Re: 1991 mariner 75 hp tilt and trim occasionally working

how do I go about hot wiring the system?

follow the cable from trim motor back into engine compartment. if the cable is 1/4x1/2 oval then you have a 2w trim motor. More likely, your cable is 3/8" round and you have 3w trim motor. when you follow back into engine cowl you will find three solenoids - starter, trim up (blue), and trim down (green). Ideally you would unscrew the blue, green, and black wires from trim and connect directly to a 12v battery. In a lazy shortcut that is not as conclusive, you can just jumper acress one of the solenoids at a time.
 

cmarbles

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Dec 22, 2013
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Re: 1991 mariner 75 hp tilt and trim occasionally working

Ok I jumped the motor and nothing, so I got a cmc TNT unit in a trade but now I have a new problem... My system is a 3wire system and the cmc a 2 wire system, does anyone know how to rig it up? I'm COMPLETLY lost....please help I do not know where to begin
 

cmarbles

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Dec 22, 2013
Messages
5
Re: 1991 mariner 75 hp tilt and trim occasionally working

Can I just get another switch and say screw the old system COMPLETLY and rig another system and place the switch up at console and possibly another near the outboard?
 

alldodge

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Mar 8, 2009
Messages
40,582
Re: 1991 mariner 75 hp tilt and trim occasionally working

Ok I jumped the motor and nothing, so I got a cmc TNT unit in a trade but now I have a new problem... My system is a 3wire system and the cmc a 2 wire system, does anyone know how to rig it up? I'm COMPLETLY lost....please help I do not know where to begin

Can I just get another switch and say screw the old system COMPLETLY and rig another system and place the switch up at console and possibly another near the outboard?

Now your loosing me. Top post, you jumped the motor and got nothing. You have a 3 wire now and also have a 2 wire and wonder how to wire it up. Then next post you wonder if you could just replace the switch. If you mean that replacing the switch will change from 3 to 2 wire that would be no.

I take it you have difficulity reading the schematic diagrams in the link I left previously. If this is that case then you cannot change to a 2 wire system. If you could understand the schematic you would see a different relay setup which would need to be replaced also to get a 2 wire to work. If you jumped the motor correctly and it does not work then replace the motor.
 
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