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7.4 Underwater

K

kevinevans

New member
Any and all help is appreciated.... I keep my 1998 Baja 232 Islander 7.4 on a trailer in a boat yard. I got a call from the owner of the yard one day letting me know the trailer jack had collapsed because of "all the water in the boat". Kids wrappers etc had apparently been discarded in the ski well, there-by making its way to plug the drain. Anyway, 7 hours after unplugging the drain, the water was out. Turns out, the jack collapse was a blessing because all of the water shifted forward, stopping the water from going into air intake.... I estimate it was under water to some degree for couple of months.

I changed the alternator the day after draining, I checked the oil and it was clean... even the trim pump that was completely under was working. I changed out the battery and the boat started right up... I ran it for approx 30 mins and experienced no hiccups.

I had 0 free time last summer so here we are six months later and nothing will work. When I turn the key, I just get one loud click.... and nothing at all from the trim pump. The trim pump bracket is completely rusted out... so I took the trim pump out to bring home, clean up and test... I also noticed a fair amount of rust on bottom of manifold.. that was the highest point of water level... Here is what I plan on doing, please let me know where I am on the right track or wrong track. Also, the bilge pump wont turn off... kinda ironic huh

1) replace starter (where the hell is it though... I crawled all over engine compartment and never saw it)

2) test trim pump.... it it works, order new bracket and reinstall.... anyone with good testing know how for the trim pump, please chime in

3) plugs look pretty good, but will replace.... I checked spark wires and they are clean with 0 rust

4) pulled battery switch... clean and reinstall.

5) ???

Thanks guys....
 
Ayuh,.... My guess is yer problems are related to the wirin' connections that were underwater,...
All the connections should be taken apart, 'n cleaned, shiny metal clean, reassembled, 'n greased for future protection...

The starter is lower aft starboard-side of the motor's block,....

Follow the Power wire,... ;)
 
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. If necessary, trace the wires to the front of the engine near the slave solenoid. One wire is grounded near there and the other is connected to a terminal. If you don't get a voltage reading at the terminal junction, apply 12 VDC to see if the trim gauge moves. If it does, check for voltage back at the trim pump connections. If there is no voltage there, apply 12 VDC there to check gauge movement.

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. 20 +/-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 penny, 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, 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 disassembled 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 grease and reinstall by aligning reference marks.
 
Used to rewind marine starters and alternators and from what I have seen......Electrical components, especially starters and alternators, that have been submerged for any length of time, may work today, but fail miserably a short time from now.

The water gets into everything, the windings, brushes, brush holder mechanisms on the starters (and rust them, making them stick), armatures and all insulating materials between the armature segments, the alternator regulator and diode packs inside the alternator and will slowly kill everything. The real deteriotion starts after they are "dried out" and the air hits them.

Easier (and cheaper) to change now than to get towed in to change later after they crap out while out having a fun Sunday w/ family.... Your call.....
 
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