Mercruiser 5.7 Tilt and Trim rewire

[slshoe2002]

Okay, Problem number one... Engine hydrolocked... fixed... so onto problem number two... The wiring for the tilt and trim guage and motor are corroded and falling apart. I need to rewire all the way back to the lower unit. Is there a trick to getting the wiring through the engine compartment and back to the lower unit? I pull but it doesnt budge. Am I going to have to take the lower unit off or am I missing something. Also, what gauge wiring is best for the project? it looks as though the previous was about 14 gauge stranded. Is there anywhere I can get wiring harnesses for this? Or should I just buy spools of wire for the job? again any insight would be great! Thanks!

 

[Bt Doctur]

Re: Mercruiser 5.7 Tilt and Trim rewire

you`ll need manual #6 ,the trim limit and trim sender come with the wiring attached. you need to remove the outdrive ,bellows and maybe the gimbal housing.
remove the locking nut, rubber grommet, and wires.

 

[tpenfield]

Re: Mercruiser 5.7 Tilt and Trim rewire

There should be a set of connectors at the rear of the engine where the trim and limit sender wires attach. I would not think that you would have to replace anything more than the senders and their attached wires.

You can get the wires out and new ones back in without dis-assembling everything, but it is a bit tricky. Best thing is to get the manual and study the pictures. Then you will have a better idea of what you are dealing with.

 

[slshoe2002]

Re: Mercruiser 5.7 Tilt and Trim rewire

yeah Id rather not remove everything if I dont have to... looks a bit tricky with alot of special tools. This is the only thing keeping me off the water at this point so im hoping it isnt too difficult.

 

[slshoe2002]

Re: Mercruiser 5.7 Tilt and Trim rewire

Im hoping someone can help me figure out what Model outdrive I have. Im trying to figure out which specialty tools ill need to accomplish this., S/N A426418

 

[slshoe2002]

Re: Mercruiser 5.7 Tilt and Trim rewire

okay so I have the trim sender and and limit switches replaced. everything is going smoothly until i try to get the lower unit to go down so I can install the hinge pins. for whatever reason I cannot get the trim to go down. is there a trick to this that I am missing? will it not go down if the sender and limit switches are disconnected? im confused and feel like im missing something simple.

 

[NHGuy]

Re: Mercruiser 5.7 Tilt and Trim rewire

If you go into manual #6 you can get all the wiring and testing info. Aside from that, remember that you can always lower the trim when everything is right. So for a no diagnostic way to get it to lower I'd say to check that all your connections are clean & tight to start with. Then if nothing happens you might test the down solenoid. You could also disconnect the battery and test for continuity in the individual wires. If the sensor wires corroded the power trim wires could have deteriorated too.

 

[slshoe2002]

Re: Mercruiser 5.7 Tilt and Trim rewire

yeah I have run a hot wire from battery directly to the down selenoid and it clicks just like when using the trim button but nothing happends. im pulling my hair out. I know everything worked when i disconnected the wiring. it was 4 wires. the wiring even had the connect plug and play. I am feeling a bit insane or stupid cant tell which. ive looked at manual 6 but but cant see the disconnect. literally the only wires disconnected was for the trim position switches. UGH! I hate wiring. will it work even though those switches arent fully installed yet? meaning I cant put them on until the hinge pin bolts are installed.

 

[NHGuy]

Re: Mercruiser 5.7 Tilt and Trim rewire

I am fairly confident, but not positive, that you can always get a down signal. I know that you need the sensors to be positioned right for the trim-up button to function. Relax, have a break and read it over again. It's always some dumb thing that was over looked.

 

[slshoe2002]

Re: Mercruiser 5.7 Tilt and Trim rewire

okay so I finished wiring up the new sensors. I was getting a click at the selonoid and nothing. Low and behold my trim pump was fried. So I replaced that. I get the up and down motion so that has finally come together. I put the outdrive back together again and everything works... but the trim guage needle still doesnt move! dang it I guess its not the worst thing in the world! any ideas what THAT could be? Also. with the instructions I received with the trim sender, it says full up should be when the hydraulics are extended to 21 3/4 but that means the whole thing from full down to full up only moves about a foot. does anybody know if thats correct? seems real low to me still.

 

[slshoe2002]

Re: Mercruiser 5.7 Tilt and Trim rewire

okay I answered my own question. trim guage is now working. had the wires backwards. I still have a question about the full up position. when the hydraulics are fully down. they measure 18 1/2. if im supposed to lock in full up at 21 3/4 thats only moving 3 1/4 inches... that doesnt seem right.