Bad solenoid wiring?

[vonBruin]

I am novice cruiser/live aboard, I am seeking the wisdom of the mechanically inclined sages of this board. I bought a Hunter 336 (built in 1995/96) the electrical/battery area was recently redone but wiring in helm station all appear to be original. The boat is equipped with a Yanmar 3GM engine that has low hours on it. So here is the problem if the boat is not on shore power the engine has problems starting. I have a portable Honda generator and can get starter battery to over 12.50 volts. Still this seems to be just short of the current needed to get the engine going, but after a night on shore power 30 amp shore power it will start. I read a bit on a Hunter site that the gauge wiring from solenoid to starter isn't heavy enough and over time will not deliver the proper charge. Just looking for confirmation if this sounds correct. Because spending weekend stuck of a private Bahama Island was an adventure but would like to have been able to leave once started getting sideway looks from the restless natives!



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[Teknishn]

vonBruin,
While it is true the not having the correct gauge wiring will affect electrical current flow...this doesn't happen "over time" unless you have poor electrical connections (over time, corrosion does occur at cable terminations which will affect current flow). However, based on what you have posted, it sounds like you may have a battery problem. After a night on shore power the batteries start the engine....Is that a one time start? Do you have problems starting after that?

A bad cell in a battery will actually discharge the battery cells around it and will not allow a battery to fully charge unless forced (i.e. shore power and battery charger), and only for a short period at that, until it starts discharging amps from the adjecent battery cells all over again.

Oh, and FYI, voltage of a battery does not neccessarily indicate a battery's ability to discharge the rated amount of amperes. It is more of an indicator of a battery's ability to take a charge.

Clean your battery terminals and make sure they are tight is where I would start. Then look at your batteries (age and condition).

Hope this helps. Might, might not, and good luck!

[model 10]

12.5 v is not enough unless you have a good sized battery bank.

[Bill Seal]

Does the starter not engage (doesn't click) or does it engage but not turn the engine over fast enough to start it?

[exMaggieDrum]

Actually having a voltage of 12.5v right after being on a charger can't tell you if it will really accept or hold a charge. Batteries that aren't being discharged but have been on a charger can hold a "surface charge" which is not indicative of anything. When doing any kind of simple battery testing you need to remove the surface charge by putting a moderate load on the battery for several minutes or a small load for longer. A surface charge won't start an engine more than once, and that would have to be on a bigger battery.

I've found on my own boat that anything over 12v would turn over the motor enough to start it (a biggish Ford Lehman). It really depends on the size of the battery bank and also to the type of battery and whether the motor has any issues or not. A bank of 300Ah batteries can start motors with low voltages. A small battery of 80Ah might not be able to. Start batteries can give more juice quickly, as needed to start a motor, but deep cycle batteries give juice slower. A big bank of good deep cycle batteries can usually start any motor, and even a smaller bank if in good shape.

The comments about checking the wiring, etc. are spot on though. If you aren't comfortable doing that you should get someone to help you or hire an electrician and have them show you how things work. One of the very first things I check are connections on the positive AND the negative side of everything to do with motor starting. I have fixed many a boat's starting problem by just tightening the connections of black negative cable going from the batteries or main negative bus - at the engine and at the bus or batteries. Of course you need to do that for the positives as well but those cables go to more places so they are more complicated.

Places to check are the battery posts, main switch posts, solenoid on the battery, smaller "baby" solenoid that "starts" the bigger solenoid on the starter, connections on the starter/solenoid itself. If the batteries are good and the connections are good you might have an intermittent ignition switch/button problem but for you I would start with the above.

Troubleshooting that and other issues other than corroded cables and loose connections will usually require a volt/ohm multimeter to check for voltages and excessive resistances in cables, wire, etc. There is also the possibility of an intermittent starter problem. I had one once on my boat where there were a couple of bad spots on the stator and when the starter ended up on those spots it would not work. Other times it started fine.

Hopefully your problems will be on the simple side. You might just need a new battery as someone said above. But always, always check for loose wires. They have a magical way of coming loose on motors and systems with all the rocking and rolling and vibrations on boats/engines.

[TurninTurtle]

12 V nominal flooded lead acid batteries are typically about 13.5 v full (depending on charger setting can be 13.8) 12.5 is low... Not low enough to say its a dead cell, but low enough to be a cause for getting the batteries checked.

Charging Information For Lead Acid Batteries – Battery University

[Lepke]

It sounds to me like the boat alternator isn't fully charging the battery. The Hunter site is saying "the gauge wiring isn't heavy enough". This could mean the boat has an amp gauge that is not a shunt type. That could mean the charge has to go from the vicinity of the starter, to the amp gauge, and back to the battery. Small wiring wouldn't be able to carry a higher charge rate. Resistance could also restrict finish charging. Especially with time and corrosion.
Problems I have seen with smaller diesels, especially those with automotive type wiring and cables is the ability for corrosion to creep into the cables and create enough resistance to block much of the alternator effort.
In tracing why an alternator tests fine on the bench but fails to fully charge batteries, I often found cheaper auto type cables. When cut open far from the terminals, the cables were green copper, partially eaten away, and had lot of corrosion. While the start current from a fully charged battery could somehow push thru to spin the starter, a proper charge current only partially reached the battery.
When helping a marina neighbor with start problems, I thought the main cables were bad. He decided on a new battery. That worked one day. So he took the battery back, had it charged and tested, and the people got him to buy a new starter. That worked one day. So then they got him to buy an alternator with the next battery charge. That worked one day. When I happened to see him again, he was putting in new cables. That worked. We cut open the old cables and they were partially eaten away. So he has spent several hundred dollars on a $25 problem.

[Bill Seal]

Don't you just love it when someone asks for help and then goes AWOL when the CF'rs ask for a little clarification.

[smac999]

sounds like you need a new battery

[Bill Seal]

Sounds like you need to respond to the thread you started.

[vonBruin]

Sorry for being AWOL, still in Bahama's with limited internet. First of thank you all for the replies. To answer some of the questions. The starter battery is basically brand new, wanted to fix problem before leaving Florida, when charged it does turn engine a couple times but just not enough to start it. I don't think it is altenator as batteries do charge when generator is running. I have two house batteries that are older but seem to still have some life in them. I also have jumper cables and tried running those from house 1 battery to starter battery but still not enough. I did have a crazy thought of trying to take battery out and do a jump of the starter when I was stuck but my sences got the better of me. Still wonder if there is a way that could work? So think it comes down to wiring that is going bad or solenoid at starter as was mentioned? Both which are taxing my limited electrical knowledge and comfort. Hope to be crossing back tomorrow and finding a good yard in expensive Northern Miami area.
Thanks for the help, sorry for delay in responding.

[model 10]

If you have a bunch of lousy batts, hook enough in series to crank the engine. 18v or 24 will spin the engine just fine. Only problem is you have to be carefull with the rest of the system. Safe way would be to wire them up to just the starter.

[Bill Seal]

If your starter won't spin a massive 60CID engine then your cables are really shot, or maybe the starter is bad. Sometimes, one brush isn't making contact, cutting the starter torque in half but still drawing the same current, or the armature is dragging in the case.
Get a voltmeter and start checking for voltage drops in the circuit.

[Cap Erict3]

12.5 volts open circuit is fine. It's the drop under a load that is the issue.

Have someone that understands electricity have a look at it with a meter.

It is likely a simple fix.

[vonBruin]

Follow up. After arriving back had immediate issue at fuel dock. So here is what it was. The starter battery was fine, the two house batteries were no longer holding charge. The big issue was the starter was seizing up. So when on shore power there was just enough power to get the malfunctioning starter to turn over.