Slave Solenoid Replacement in merc 3.0L

friendly_jacek

Seaman Apprentice
Joined
May 12, 2008
Messages
48
OK, for the last several months, the I had intermittent clicks in the power trim and starting system. I did some diagnostics and narrowed it down to bad solenoids (yes, all 3 of them, what a POS). Yesterday I spent a considerable amount of time trying to remove the slave solenoid that is bolted to a plate next to the engine. The nuts spin happily with the bolts and there is no way to hold the bolts from behind. Now, what are my options beside drilling the bolts out. I thought it was supposed to be simple.
Anyone, please?
 

Fishermark

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Oct 19, 2003
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5,617
Re: Slave Solenoid Replacement in merc 3.0L

Drill... cut... grind... depends upon the access and what tools you have.

I thought it was supposed to be simple.

Never assume that on a boat! Especially if you do any boating in salt water! ;)
 

tommays

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Jul 4, 2004
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Re: Slave Solenoid Replacement in merc 3.0L

47b7d700b3127ccebc7811c6595a00000036100AaOWLZq3ct2IA


You want rusty i give you rusty ;)


I even got it all apart and on a new trim pump frame BUT only experance will teach you what is cheeper to break apart than spend time fixing
 

Bondo

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70,464
Re: Slave Solenoid Replacement in merc 3.0L

slave solenoid that is bolted to a plate next to the engine. The nuts spin happily with the bolts and there is no way to hold the bolts from behind.

Ayuh,.....

Take the Plate Off,+ you can reach the bolt heads,...........
 

friendly_jacek

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May 12, 2008
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48
Re: Slave Solenoid Replacement in merc 3.0L

Thanks for all the answers. I will try it next weekend armed with drill and hammer.

BTW, are these solenoids that fragile? I have very few hrs on the boat (~50). Looks like the slave solenoid and both trim solenoids are bad. Fortunately, I found them cheap on ebay and bought even a spare one.
 

Fishermark

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Re: Slave Solenoid Replacement in merc 3.0L

It would be unusual for all three solenoids to go bad at once... but not so unusual to have corroded connections. Are you sure your solenoids are bad? Did you rule out bad connections? Do you have a good ground? Have you tried the new solenoids before mounting them? (Making sure the grounds are connected as necessary).
 

friendly_jacek

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Re: Slave Solenoid Replacement in merc 3.0L

It was not at once. The solenoids would click and after enough clicking the starter/pump would engage. It started over a year ago and got progressively worse to the point that they mostly don't work (and yes, I tested). At the same time the boat was hardly used (only once in 2007). Maybe they fail from disuse and corrosion?
 

wkb2460

Petty Officer 2nd Class
Joined
May 4, 2008
Messages
146
Re: Slave Solenoid Replacement in merc 3.0L

South Jersey Marine Outlet in Maple Shade NJ sells a stainless steel bracket to replace the rusted steel one. His prices are very fair.
856-482-1500
 

Bondo

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Re: Slave Solenoid Replacement in merc 3.0L

It was not at once. The solenoids would click and after enough clicking the starter/pump would engage. It started over a year ago and got progressively worse to the point that they mostly don't work (and yes, I tested). At the same time the boat was hardly used (only once in 2007). Maybe they fail from disuse and corrosion?

Ayuh,......

I'm bettin' that Fishermark is Right,.....

If you removed, sanded, cleaned,+ reinstalled All of the Wiring Connections,...
You probably wouldn't need Any solenoids at All......
 

friendly_jacek

Seaman Apprentice
Joined
May 12, 2008
Messages
48
Re: Slave Solenoid Replacement in merc 3.0L

It would be unusual for all three solenoids to go bad at once... but not so unusual to have corroded connections. Are you sure your solenoids are bad? Did you rule out bad connections? Do you have a good ground? Have you tried the new solenoids before mounting them? (Making sure the grounds are connected as necessary).

Ayuh,......

I'm bettin' that Fishermark is Right,.....

If you removed, sanded, cleaned,+ reinstalled All of the Wiring Connections,...
You probably wouldn't need Any solenoids at All......

Thanks for the input. Like I said, the solenoids were faulty and I tested them before starting the work. The connections in my boat are tight and clean. The reinstall of 3 solenoids took way more than half of day. I thought the slave one was hard, but it was even harder to reinstall the pump ones due to limited access in 175. Now, everything works like it should with no clicking. I believe the OEM part was likely defective and I went with Sierra part to be safe.

This brings the biggest dissatisfaction with my boat. Carburetor, solenoids, connections by screw and nut. This is a technology from early 1900? if not late 1800?. In a boat made in 21 century. If the engine had modern relays and fuel injection, 98% of my problems with the boat would be eliminated (I also have a bad case of dieseling and very hard starts and will attempt the mixture screw adjustment).
 

Don S

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Messages
62,321
Re: Slave Solenoid Replacement in merc 3.0L

Welcome to the REAL world.
Here, you find it's sometimes necessary to pull the engine to do (what used to be) simple things. Like replacing a raw water pump impeller, or changing a starter, or perhaps a simple tuneup.
Mercruiser, in the last few years, has done everything in it's power to make it impossible to work on their engines. Not only the raw water pumps, but the fuel pumps under a motor mount in some stupid plastic box that takes a rocket scientist a week to put together with a robot, but a marine tech has to do with one hand, by feel down in a deep hole. And has to do it in less than an hour or the customer screams rape.
I have never seen 3 relays go at one time. Not sure what your real problem is, but it's not that they failed, but why! Why, did 3 relays fail on an engine that is only 4 or 5 years old.
 

rodbolt

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Sep 1, 2003
Messages
20,066
Re: Slave Solenoid Replacement in merc 3.0L

normal slave relay failure is due to excessive moisture and or low voltage burning the main contacts, thats why you can click them several times then they suddenly work. the plunger disc has to make contact between the min stud terminals.
the click indicates the plunger moved, the lack of voltage on the load terminal indicates no contact between the disc and the terminals.
low voltage causes burn marks which are non conductive, moisture causes corrosion which is non conductive.
cut one open and see if I am right :).
I finally figgured it out though, boats are simply not designed to get wet, get them wet and they break, keep them dry and all is well.
I agree with DonS about the idiotic fuel pump though, last pair I did,water damaged, was in a 27 albermarle with twin 5.7 MIE MPI motors, only took 14 hours to change 2 pumps and realign the shaft couplers :)
could have been worse I guess, they could have been V drives.
 

friendly_jacek

Seaman Apprentice
Joined
May 12, 2008
Messages
48
Re: Slave Solenoid Replacement in merc 3.0L

normal slave relay failure is due to excessive moisture and or low voltage burning the main contacts, thats why you can click them several times then they suddenly work. the plunger disc has to make contact between the min stud terminals.
the click indicates the plunger moved, the lack of voltage on the load terminal indicates no contact between the disc and the terminals.
low voltage causes burn marks which are non conductive, moisture causes corrosion which is non conductive.
cut one open and see if I am right :).
I finally figgured it out though, boats are simply not designed to get wet, get them wet and they break, keep them dry and all is well.
I agree with DonS about the idiotic fuel pump though, last pair I did,water damaged, was in a 27 albermarle with twin 5.7 MIE MPI motors, only took 14 hours to change 2 pumps and realign the shaft couplers :)
could have been worse I guess, they could have been V drives.

It totally makes sense but I thought they were sealed?
 

djfiling

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Apr 10, 2012
Messages
1
Re: Slave Solenoid Replacement in merc 3.0L

How did you get it off. My nuts spin also.
 

Don S

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Re: Slave Solenoid Replacement in merc 3.0L

How did you get it off. My nuts spin also.

Welcome to iboats.
You are asking questions on a 4 year old thread of someone elses. Your best bet would be to start a new thread of your own and ask your question using your engine info and maybe a picture showing your problem. Wrenches are the normal means for holding spinning nuts.
 

muelled

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Jul 10, 2007
Messages
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Re: Slave Solenoid Replacement in merc 3.0L

OK, for the last several months, the I had intermittent clicks in the power trim and starting system. I did some diagnostics and narrowed it down to bad solenoids (yes, all 3 of them, what a POS). Yesterday I spent a considerable amount of time trying to remove the slave solenoid that is bolted to a plate next to the engine. The nuts spin happily with the bolts and there is no way to hold the bolts from behind. Now, what are my options beside drilling the bolts out. I thought it was supposed to be simple.
Anyone, please?
Ran into same problem, but solution was simple. The solenoid body was held to it's base by 4 metal tabs. I bent these back and took out the solenoid. I did the same on the new one, put it in the old base, (using the new rubber gasket) and bent the tabs in place with a screwdriver. Took maybe 30 minutes, including replacing the wires. Good luck
 

Don S

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Messages
62,321
Re: Slave Solenoid Replacement in merc 3.0L

Please look at the dates of the posts before replying, this one is from 2008. I'm sure he has the problem fixed by now.
 
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