ignition selonoid

rasbury

I was trying to find a thread that was already started, but, someone was having issue with turning the key and getting nothing...and keep at it and it starts which I am having also. They mention and several chimmed in that there is some sore of selonoid (not at the starter but on top of the motor) which I see in the manual but can't really determine where it's at....is the starter at the back of the motor like a car? If the starter has a selonid on it which looks like it does from the manual, what is this other one for??

TikiHut2

It's a slave solenoid on top of the engine right behind the carburetor/flame arrestor. A short jumper accross the contacts will tell you if it's done.....and to get you home in a pinch.
mike

Black_Diamond

Rasbury: on the merc v-8, the solenoid is on top of the engine, behind the throttle body by the red button circuit breaker.  It is the same solenoid used for the up/down drive pump trim (2 per pump).  $20 part.  You still have a starter solenoid too, but this one just lets the key not have all the big wiring.  Any Merc dealer would have it in stock as they  are a common part to replace.

rasbury

thanks, I see a continuity test you can do on it once energized so I will check it out...right now it's intermittent but sounds like the problem and makes sense why it's here. I was going to go through all the ignition connections and the manual is not a lot of help.....I need to start with the fuse panel where the selector switch for the battery is and make sure all the connections are good going back..I did notice on the battery side back on the transom somewhat of a bus bar back there that was interesting...looks like a good place to have corroded connections as it is exposed....as always, much much to learn!

Black_Diamond

that bus bar should be your grounding block.

you can jump the solenoid too next time it acts up, it will let you know if that is the problem.

rasbury

yep, need to check it out and also that bus bar- guess that is ground for things you like to work...someone mentioned another one behind the bat isolator switch?

rasbury

black= if you jump it, is that telling you it is bad or the ignition is bad? I am thinking if you can put power to it and make it work, that proves it is ok and some thing else is wrong?

Black_Diamond

with the ignition on, and it won't crank, then jump the solenoid and it cranks, most likely the solenoid.  Worse case: $20 and spare for the trim pump  when its time is up.  

rasbury

I have the manual and will try to get out there and take a look....we are so over the rain here this year in Fl, the plus is the rivers and lakes should be full through to the spring this year but dang, turn it off! In about 3 years, when we have a dry year, we will have the fires all over again from all the brush that is growing......thanks black.

rasbury

well, I did find it, but since it is working 99%, I could not test it. When I first went out I turned the key and nothing...turn it again and many other times bumping it and no problem....but assuming this is the problem and it fails where else but the middle of no where, I do not understand the jump....is that jumping from one side to the other or, juice from the battery to the other side of it to bypass the valve? And as long as there is juice, the starter is on as well, correct???

rasbury

I think Tiki answered that....from one side to the other....but still, as long as that connection is made, the starter is engaged, right?

Dream_Inn

Ras, yes, with the key turned and jumpering that solenoid, the starter will engage.

212rowboat

You're over thinking it, ras.... on that device (slave solenoid) side in battery is always hot... Side on starter relies on device to power it... when you turn the key the relay between those posts connects them.  of slave solenoid has bad relay, the gate won't close when you turn the key, and starter won't engage... When you jump the posts, the starter will engage whether you turn the key or not. ... That solenoid protects another solenoid that's mounted either in or on the actual starter, and exists solely because running heavy gauge wire with that much power to the helm (key itself) is expensive and has an element of danger to it. 

rasbury

10-4, may or may not be our problem as it has not failed completely. I did notice while looking this over there was another "device" right with it, does not appear to be part of the ignition looking at the shop manual but looked like some corrosion going on with the wires...was going to post a picture but once again the rain shot me down but will keep looking at that and getting more familiar with the motor layout- sure a lot more to this than the 3.OL in my last boat. I can't even reach and find the starter, would you have to yank the motor to change it?

212rowboat

Yeah, good pretty much need to lift the motor to change it, or have a bucket of patience handy, and then some... 

If your starter is.dead it would likely make funky sounds when it charges, primarily the throw out lever... 

The explanation you gave is typical of a solenoid dying, as it works most the time, then some of the time, then not at all when they're in their death throws. and remember, the solenoids, especially the slave solenoid, are there to protect your starter and are sacrificial... Most likely it is that solenoid. 

TikiHut2

...and it goes on...... Just change the $15 slave solenoid and be done with it. You hopefully don't wait for a tire to blow before changing them, if it's showing signs of eminent failure just change it.

Changing your starter is the last thing you want to try with the engine in the boat. Just change the slave solenoid......... oh yeah. Change the slave solenoid, it's failing.

Just sayin'

rasbury

Whoa! Not going after the starter, just looking at the motor and the manual and the ignition system- and it just kind of hit me, how the heck would you ever get to the starter! I am replacing that and getting a spare for the trim as it kind of does the same thing- hit the button and zip and then keep hitting it and it works so sounds like the same problem in two locations. And I did replace a tire on Saturday that had not blown yet........lol

TikiHut2

Oddly, my starter slave solenoid failed within a week of my trim solenoid. If you do the trim solenoid just do both the up AND down at the same time. It'll be far simpler than waiting a few weeks for the other one to fail...... it's that eminent failure deal again.

Hope your enjoying your boat. It sounds like your learning the proverbial ropes.
Mike

rasbury

but they end up around my neck somehow......

rasbury

would this also cause a "slow" starter? When I start my boat it always sounds like it's going to kill the battery before it catches and starts, not a real strong start like say a car...now I have figured out my raw water pump is bad and eventually froze which I have not yet resolved which could have been an obvious drag on the system...and then we have this slave cylinder issue which if not connecting properly could be limiting the power in the system....need to get the boat home and get to work. When I an charging the batteries, does the isolator switch need to be on or does it matter?

rasbury

what about the isolater switch when charging, does a battery have to be on to charge? It does not seem to get any better during the day like it charges while running..something going on....

rasbury

yepper's, didn't think so, thx. I will have to chase down all the ignition wiring and make sure everything has a good contact then....

TikiHut2

If your batteries are topped off and you're still having a slow rpm start RY may have a point on a bad ground conn. It's not easy to get to but on one of the upper starboard side bell housing bolts underneath the hydraulic steering ram you'll find a cluster of ground wires(or possibly even two clusters) bolted to the block under a bell housing bolt.

I have a shop full of wrenches but only one that was the perfect length and angle to get a serious bite on that cursed nut. Get it tight and your slow/hard start MIGHT go away.  I do not recommend trying to take them completely off to visually inspect them unless you're committed to some serious anger management.

Pull and clean all your battery terminals and slave solenoid connectors too(even if they look good). If it's still an issue even after putting in a new solenoid then you may have a battery cable failing internally. That usually happens near an end connector but can happen anywhere there had been a nick or mfg defect in the insulation.

Good luck.
Mike

rasbury

10-4 Mike, I'll get it back home next week to tackle the water pump and slave selonoid, maybe I'll get lucky and that will resolve it...

rasbury

ok, two questions as now the boat barley sounds like it wants to start like dead batteries. Please resist that comment. So, we have been talking about testing the starter slave selonoid. I have a set of jumper wires, one side with big clamps and the other side probes like a meter tester, made it for something...anyway, I pulled to wires off their posts and you have the two posts that line up front to back to the boat and then the larger terminals on the top. Does it matter which to jump? I tried it and it clicked and clacked like it was connecting, but did not seem to be able to power the starter either. So, Can I one either of these posts/ terminals use my jumper caples and say bi pass the cylinder so I am sending power to the side of the slave cylinder that would power the starter selonoid and assume the larger posts and for sure know it is the slave cylinder bad??

Next one is tuff. This has been an issue since purchases, just worse. I replaced the batteries by swapping out the same as what was in there. I am starting to wonder,and don't know much about batteries, what CCA etc. should be in there for the 2005 MPI 350 motor? I know I will get a variety of opinions but would like to know what mercruiser would set the boat up with when sold new.

Michael T

The newer boats with EFI or MPI engines and their energy requiring electronics should be fine with 900 or more MCA (marine cranking amps). Some techs say that anything above 800 MCA is okay but I prefer above 900 MCA.  The term CCA means cold cranking amps and is used more for automobiles that must be started as low as -40. Very few boats need to be started at anything near that so MCA are used.  CCA (cold cranking amps) are a measurement of a battery's capability at 0 degrees F wheras MCA (marine cranking amps) are the measurement of a battery's capability at 32 edgrees F. My 350 mags with Axius used batteries with 1000 MCA and I am using 1000 MCA for my 2014 8.2 Magnums with Axius and that is a whack of an electrical load which the 1000 MCA AGM batteries handle fine. MT

rasbury

10 4 Mike I will check mine am but do not think mine are that high...

girls2water

I believe I have the selonoid issue going on as well.  I have a 232 captiva 5.7 mercrusier -  1998.  Where the selonoid is by the red button there is a cover on the selonoid called a mercothode.  4 cables attached at bottom and 2 screws at either end.  I am not clear on which screws you do this jump on to check the slave selonoid.  the top screws sit lower then the top of the mercothode cover and so you couldn't just lay a screwdriver across for the jump, if those are the screws.  OR do I have to take this cover off to get to the screws to jump?  Is there anything here I could seriously mess up?  boat mechanic said I can mess up the OEM?  (I think those are the initials he used).  and would be a 1000 repair.  The only other thing in my series of several attempts to start and only click to now won't start at all is - my son hit the kill switch and it seems like ever since then we had the starting issue and it has gotten continually worse (coincidence or something to look for that might not have reset properly).  Thanks

rasbury

girls, only way to know is get familiar with a volt meter...I'm trying as well.

Now then, here is how I tested mine per the manual. I removed the small post pull offs and marked them and then the larger posts and marked them. Had two jumper wires from the battery, positive was on the near post to me and ground the rear, set the voltmeter to continuity and tested. I can here it click but it did not read anything on the meter. So I pulled it off and tested it again and now seem to get a reading. I like the meters that make an sound instead of a gage. Anyway, I will test it again as it's hard to have four wires going on and know everything is connected so I know the test is accurate.

Also, looking at my battery I was surprised to what I found. I have attached a copy of the label and it appears it was not a large enough MCA as I thought- I replaced what was in the boat. With this lower amp battery, it did start but weak, would it eventually killed the battery by over drawing the battery for the last 8 months or so? Some the battery sites I looked at showed with CCA ratings what normally is a comparable MCA battery, the MCA on this battery was lower. Electrical stuff drives me nuts and I know that is a bad problem to have and own a boat! 

rasbury

Black_Diamond

An undersized battery will have a shorter life since you'll pull a higher ratio of amps to battery capacity than a correct sized one (larger) during starting.  Not to mention the voltage will drop and that can effect your MPI/electronic ignition too...drops too far and it will not work even though the engine might crank.