Replacing Or Rebuilding My Mercruiser Bravo 3 Trim Cylinders - Start To Finnish

Filled and top off my Reservoir with gear lube - Quicksilver Trim Fluid 92-858075Q01






and also greased my Lower Units gimbal bearing zerk fitting

 

Ok, now I noticed the my Trailer Switch (WHITE) is working up and down.
and my trim Switch (Black) is only tilting down, the up is only working when I have the Trailer Switch (WHITE) Pressed.

The Trim Tilt (BLACK) is supposed to work on its own, to prevent over tilting when in water.




I found some Instruction on how to trouble shoot is below.


"If the OD goes up with the TRAILER switch and not the trim switch, proceed with below *.

If not, the motor shaft may be sheared at the valve body of just worn out and to weak to pump fluid. Valve body filters may be plugged. DO NOT ATTEMPT TO ADJUST THE VALVE BODY.

Disconnect the cylinders at the prop end and see if they move in and out in unison. If they do, the motor is worn and can't handle the load of the OD. If they don't, the valve body or the cylinders need work. If you don't have the hydraulic test equipment take it to a professional.






* How the trim/tilt works

Before you tear anything apart or replace wiring and switches, test it out; first by visual inspection by pulling back and forth on the wires while operating the switches and then test with a meter.

At the commander switches,

the red wire will always have 12 volts.

The green wire gets 12 volts when the trim toggle is held down.

The blue wire gets 12 volts only when the toggle is held up or the trailer switch is pushed in. The purple wire is part of the limit switch circuit.

If the switch voltages are as they are supposed to be

then go to the trim/tilt pump assy. and make sure the purple wire connector (single wire) and the blue wire connector with two blue wires on one side of the connection are not corroded or loose.



These are the trim position and limit switch wires. Pull them apart and inspect; they should be clean and tight; reconnect them.

Next check the three wire connector (RED, BLUE & GREEN) at the pump assy. This plug can vibrate loose and cause your problem. Pull it off and see if the pins are clean and not corroded; reconnect it.

The RED wire in the plug sends 12 volts from the pump assy. to the toggle up/down and trailer up switches. The BLUE & GREEN wires bring 12 volts from the toggle trim/tilt and trailer switches to the two solenoids on the pump assy.

The GREEN wire goes to the DOWN solenoid while the BLUE wire goes to the UP solenoid.

Did you check the switches with an ohmmeter? The trim/tilt switch is a 2-way switch and will show continuity only when it is toggled in each direction between two of the wires.

Up toggle connects the RED wire to the BLUE wire. Down toggle connects the RED wire to the GREEN wire. The TRAILER UP switch also connects the RED wire to the BLUE wire.

The OD trim limit switch will only send voltage to the trim/tilt switch in the upward toggle position if the OD limit switch is below the adjusted trim limit that keeps the OD being out of the water.

To test the limit switch circuit, lower the OD to the down position and slowly raise it with the trim toggle up until it stops. Then measure the distance between the trim cylinder attaching bolts. If the distance is approx. 22 +/- 1/4 inches, then the trim limit switch is adjusted properly and the commander trim toggle switch is working in the up/down mode.

Go to the trim/tilt pump assy. and make sure the purple wire connector (single wire) and the blue wire connector two blue wires on one side of the connection are not corroded or loose. Pull them apart; they should be clean and tight; reconnect them.

Next check the three (RED, BLUE & GREEN) wire connector at the pump assy. The RED wire in the plug sends 12 volts from the pump assy. to the toggle up/down and trailer up switches. This plug can vibrate loose and cause your problem. Pull it off and see if the pins are clean and not corroded; reconnect it.

The BLUE & GREEN wires bring 12 volts from the switches to the two solenoids on the pump assy. The GREEN wire goes to the DOWN solenoid while the BLUE wire goes to the UP solenoid.

Disconnect the trim/tilt assy. wires from the battery and then check each of the nuts and studs on the solenoids for clean and tight fittings. Each solenoid has three wires and the buss bar connected to it. The bases of them have a black ground wire and a small blue wire to one and a small green wire to the other.

On top of each solenoid, the large BLUE wire from the pump motor attaches to a large copper stud with the solenoid that has the small blue wire at the base while the large GREEN wire from the pump motor attaches to a large copper stud with the solenoid that has the small green wire at the base.

The other copper solenoid studs are connected together with a copper buss bar. One of the two studs will also have a funny looking 110 amp fuse attached to the bar. The large RED wire from the battery connects to the 110 amp fuse. This large red wire is the power for this buss bar. A small RED wire attached to the bar stud sends 12 volts to the switches which in turn sends the 12 volts to the solenoids which turns on the pump motor.

Important: if the studs on the either solenoid are dark and not like a clean penney, especially the BLUE wired solenoid, this solenoid is failing due to age and/or a loose bottom copper stud nut. The dark color comes from heat generated inside of the solenoid by the contactor because it is arcing like welding similar to points wearing out. Change the solenoid.

Cleaning Trim Limit Switch & Trim Position Sender

For the trim/tilt problem you are experiencing, if the wires from the limit switch (port side) and trim position sender (starboard side) are in good condition, they (Switch or sender) can be disassembeled to clean out the old hardened grease. SCRIBE the sides of each one and the OD for a reference mark before removal. Clean out the old grease and pump fresh Mercruiser 2-4-C grease thru the zerk fittings before reinstallation. Clean the small brass contact points with solvent and a pencil eraser until shiny; repack w/ 2-4-C grase and reinstall by aligning reference marks."

 

I cleaned off my Bravo 3
Trim Sender & Limit Switch for the Port side, need to do the Starboard

 

Working my the Starboard Side of my Bravo 3 Trim Sender & Limit Switch and had to take a rain break LOL

A look under the cover



Took out to clean up the grease from the contacts.




Took out to clean up the grease from the contacts.
Definitely different contacts on the Starboard then the port side.





Finished the Starboard Side.




But needed to take a rain break, before I take a second look on the inside of the Port Side. Because I greased my zerks and that may have put some grease onto the contacts? I wont know until I take a look.

Yup it is down pouring now :-(

 

Ok rain stopped, so I went back out and took a second look at the Port side and all looked good.
Put in back on and the lower unit still only goes up with the trim Switch (Black) AND Trailer Switch (WHITE) Pressed.

Not sure how to check to see if the Trim Sender & Limit Switches are bad?

Does anyone know how to check them out?



I may have to buy new ones?
Mercruiser Trim Tilt Sender Kit Alpha/Bravo 805320A03



https://www.amazon.com/dp/B001QX5Q2W/?tag=shrimpflforum-20

 

Could also be my Trim Relays?

Testing and Bypassing SPDT Power Trim Tilt Relays for Boats

Photo of my relays

 

Left is the Trim Switch
Right is the Trailer Trim Switch

I can jump the wires om the Trim Switch to make it go down,
but when I jump the up wires it does not move the lower unit?
Not sure what that means yet?

 

Found the Problem by doing the following:

I just went up on the boat and jumped the Purple Wire and The Blue and White Wire from trim pump wire harness side. And it did the trick, worked both up and down with the (Black) Trim Switch.

Labeled with blue tape so I know which is which when I install the new Trim Sender & Limit Switch.






So Now I will order some new Trim Sender and Limit Kit.

https://www.amazon.com/dp/B001QX5Q2W/?tag=shrimpflforum-20

 

Ended up ordering OEM parts.

Mercruiser OEM Trim/Tilt Sending Unit Limit Sender Kit 805320A03,805129A3,805130
Company website
http://www.leadersrpm.com/home-index.asp

Amazon product info
https://www.amazon.com/dp/B001QX5Q2W/?tag=shrimpflforum-20




talked with a engine mechanic over at
http://www.marineengine.com/

 

Looks like I should be able to get to the out-drive wiring bolt with a swivel socket extension


A look at the wiring from the outside of the outdrive unit









A look at the wiring from the inside of the outdrive unit




Connected my Trim Motor Pump Bracket back onto the Stearn Wall.

 

Got the bolt out using a 11MM long extension swivel socket and a spot lights to see the bolt, took about five minutes.

Cut the wiring on the inside of the Stearn, and clipped all the wire zip clips,

ordered a OEM Mercruiser Trim Tilt Sender Kit Alpha/Bravo 805320A03
https://www.amazon.com/dp/B001QX5Q2W/?tag=shrimpflforum-20

Should go in just as easy. The wiring had a white grommett attached to them making the wiring water proof, so the new ones should as well.

 

Nope, or I would be installing them LOL

 

My OEM Mercruiser Trim Tilt Sender Kit finally arrived in the mail.

Alpha/Bravo 805320A03
https://www.amazon.com/dp/B001QX5Q2W/?tag=shrimpflforum-20

So I will install them soon.

 

OK since I was delayed in finishing my install, because of the hurricane and weather conditions. And now with the Red Snapper season starting soon, I derided to complete my Trim Tilt Sender Install.

Removed the old Trim Tilt Senders




And installed the new Trim Tilt Sender Kit Alpha/Bravo 805320A03
By following the instructions in the kit.




I needed to use the below tools to fish the wiring




After fishing the wiring, I installed the bolt and holding the wiring in place.

Adjusted my trim, and everything seems to be working properly.

 

Finished my Trim Tilt Sender wiring today by using heat shrink butt connectors. Put all wiring back in the flexible cable protectors, and zip-tied everything. Everything is working like new.

Now waiting for the seas to calm down, so i can take her on a test run.