Motor not turning over - looking for ideas

[PatrickF]

I have a GB 42 with twin Cat 3116s. I shut them down six days ago with no signs of trouble. I went to start the port motor today and nothing but a loud “click” from the double solenoids. Batteries are fully charged, Starboard motor started fine. I verified it’s not the neutral switch. After turning off and on the various battery switches a few times the motor cranked. It has cranked several times since, but if something is failing I’d like replace it before it fails while boating. It doesn’t seem to be the starter or solenoid but maybe they were stuck originally. Any ideas on where to look for issues? Thank you.

 

[RT Firefly]

Greetings,
Mr. PF. Do the simple cheap stuff first. Remove, clean and re-install ALL battery connections (High current draw) with appropriate anti-oxidant coating. Next do all other power (low current draw) connections the same.
Sounds like you have enough juice to energize the solenoids but not enough to turn the starter.

 

[luna]

Your boat was built in 1993, about 32 years ago. Things get oxidized over time. You said after cycling the battery switches a few times, the engine that would not crank, cranked. You did not state if the engine started.

On the engine that did not start try this, as a test only.

From the circuit that includes the engine that did not crank, remove the negative battery connection.
Remove the wire that is connected to the battery from the the battery switch. Remove the wire that is connected to the engine from the battery switch. Take these 2 lugs that are crimped on to the wires that you removed from the battery switch and clean them. Then using a suitably sized bolt, washers and nut, bolt the lugs together tightly.

Reinstall the negative connection to the battery.

Does it crank and start now?

Remove the bolt and separate/insulate the 2 lugs.

 

[SteveK]

Do you have separate start batteries and can they be combined. Try that as well if not done. Eliminates a possible bad/weak battery

 

[Comodave]

Greetings,
Mr. PF. Do the simple cheap stuff first. Remove, clean and re-install ALL battery connections (High current draw) with appropriate anti-oxidant coating. Next do all other power (low current draw) connections the same.
Sounds like you have enough juice to energize the solenoids but not enough to turn the starter.

This is where I would start. Even if it isn’t the problem it is good routine maintenance. Then look at the starter solenoid.

 

[wkearney99]

Starting pulls an enormous amount of electrical current. If there are any loose connections or corrosion that have developed the wire will lose it's ability to pull the necessary amount of current. So while you might be able to check a wire for voltage readings, that alone won't tell you if the wire is capable of pulling the necessary current.

That's why it's a good idea to start with loosening/removing existing connections for the high-current wires for starting. At the battery, at the starter and at the various switches/solenoids. If you see any signs of corrosion while doing this understand that it can creep into the cable ends. Corrosion inside the ends of cables results in blocking them from being able to carry full starting current. This is additionally dangerous because now you've got breakers/fuses that still think the wire is capable of handing high-amperage. The corrosion blocks it and overheats, while the breaker doesn't trip. Fires start this way.

Troubleshooting electrical gremlins is time consuming, and expensive if you're having someone else do it. It's hard to predict where, but there's a line where you eventually waste more money debugging a problem versus doing a 'rip and replace' job. As in, "oh joy, now you've spent way to much money discovering you should have just yanked it all to begin with". Been there, spent that...

 

[High Wire]

Loose or corroded battery cables including the negative. Don’t forget to check behind the battery switches.

 

[Nick F]

I also have a Grand Banks 42 although mine is 1974. For some years the GB had an "automatic parallel switch" system and your boat may have the same setup. If so, the following applies:

When you press the starter button it energises a solenoid (located behind the main disconnect switches on the engine room front bulkhead) and this solenoid joins the port and starboard batteries together to give more oomph to the cranking.

At the same time, the starter button also energises the solenoid right at the side of the starter motor which in turn sends current to the starter motor actuator.

So, it is very helpful to know where the click sound came from. If the sound is only from the disconnect switch panel then very likely you have a sticky solenoid at the starter motor. This is a common issue and the solenoid should be replaced (not an expensive item). Of course, if the problem has gone away then the diagnosis is difficult/impossible. In this case I, personally, would replace the starter solenoid anyhow.

If the problem returns before replacement of the starter solenoid, have someone hold the starter button pressed and tap the starter solenoid with a hammer. Very often this will cause the starter to engage. In this case, it is 100% confirmed that you have a "sticky" starter solenoid.

 

[Discoverer]

Your issue is likely caused by a bad connection, a weak solenoid, or an intermittent starter circuit problem. Check all battery cables, grounds, and connections for corrosion or looseness, and inspect the starter solenoid and relay for wear. Try tapping the solenoid or jumping it directly to isolate whether it's a wiring, switch, or component failure before replacing parts,

 

[O C Diver]

Always good to have another person holding a volt meter on the battery when trouble shooting.

If no voltage drop, my assumption would to down stream of the solenoid that you here.

If there is a cable connection on the down stream side of the solenoid, check for voltage there when cranking.

While there may be other possibilities, my guess is that the solenoid is not closing enough to make electrical contact or you may have a brush or armature issue within the starter.

Start by checking voltage to the starter before getting out the tools.

Ted

 

[KnotYet]

I have used a battery jump pack to streamline the troubleshooting process.
Connect the pack to the + terminal and ground of the starter before the starter
solenoid. If you can crank the engine normally then that eliminates the starter.
If not, then it's the starter or its connected solenoid. Rinse and repeat.

 

[SIBERNUT]

Time for one comment. I would try to bar the engine over first. Your problem is "probably" electrical. But it is not beyond possible an injector has leaked & created a hyd. Lock. If so, hitting it with that much juice has been known to bend a rod. Just see if it moves is enough.

 

[Comodave]

Time for one comment. I would try to bar the engine over first. Your problem is "probably" electrical. But it is not beyond possible an injector has leaked & created a hyd. Lock. If so, hitting it with that much juice has been known to bend a rod. Just see if it moves is enough.

That is certainly a possibility, I hadn’t thought of that one.

 

[mvweebles]

Time for one comment. I would try to bar the engine over first. Your problem is "probably" electrical. But it is not beyond possible an injector has leaked & created a hyd. Lock. If so, hitting it with that much juice has been known to bend a rod. Just see if it moves is enough.

That is certainly a possibility I hadn’t thought of that one.

From the OP: "I went to start the port motor today and nothing but a loud “click”

Hydrolock was my first guess too. But I am, at best, a passable shade-tree mechanic. TF has much better gear-heads than me. But it is in the realm of possible troubleshooting scenarios.

Peter

 

[SteveK]

After turning off and on the various battery switches a few times the motor cranked. It has cranked several times since,

Also from the 1st post. Where is the OP anyway?

 

[SeaDogAK]

It sounds to me like it could be a starter solenoid. Mine did exactly this when a solenoid failed.

 

[captjohn7]

I have a GB 42 with twin Cat 3116s. I shut them down six days ago with no signs of trouble. I went to start the port motor today and nothing but a loud “click” from the double solenoids. Batteries are fully charged, Starboard motor started fine. I verified it’s not the neutral switch. After turning off and on the various battery switches a few times the motor cranked. It has cranked several times since, but if something is failing I’d like replace it before it fails while boating. It doesn’t seem to be the starter or solenoid but maybe they were stuck originally. Any ideas on where to look for issues? Thank you.

I have a 1979 42 classic that had the same problem. It turned out to be the original battery cable (47 years old)that have corroded enough inside that it wasn’t conducting enough amperage. Hope this helps.

 

[johnma]

Older starters can sometimes stick. Tap very lightly on the housing with a small hammer. Also, check your neutral safety switch.

 

[Deckape]

Remove and clean all connections. It’s usually the ground

 

[woodlord]

Did you check to make sure that it’s not in gear

 

[Sailinggod]

I have a GB 42 with twin Cat 3116s. I shut them down six days ago with no signs of trouble. I went to start the port motor today and nothing but a loud “click” from the double solenoids. Batteries are fully charged, Starboard motor started fine. I verified it’s not the neutral switch. After turning off and on the various battery switches a few times the motor cranked. It has cranked several times since, but if something is failing I’d like replace it before it fails while boating. It doesn’t seem to be the starter or solenoid but maybe they were stuck originally. Any ideas on where to look for issues? Thank you.

One comment I haven’t seen (although I didn’t peruse all of them) is the possibility of a “flat” spot on your starter motor. You had enough juice to activate the solenoid but the engine wouldn’t crank, and then it did. Sometimes this moves the starter just a bit in order to make a proper connection. The test for this if it happens again is to tap the starter with a hammer. If it cranks, then it’s likely a flat spot and time to rebuild or clean the starter armature.
Good luck. Hope it is simple to fix.

 

[Dale Barwick]

This is where I would start. Even if it isn’t the problem it is good routine maintenance. Then look at the starter solenoid.

I would bet it's either the solenoid or the starter I would try the solenoid first as they're not that expensive and easy to replace. If you know how to test if you have somebody turn it on so the solenoid clicks and see if you have 12 volts output on the output side or both sides should actually be 12 volts with the key turned to the start position. But starting intermittently like that typically is a solenoid is wearing out and needs to be replaced

 

[kirkll]

Checking a starter solenoid and starter issue is pretty basic stuff . You can easily just jump the posts with a screwdriver , which in essence bypasses the solenoid. If the starter turns over doing this with the key in the on position, and it fires up ok, That tells you the solenoid is toast. If it's still just clicking, or getting nothing at all after jumping it directly. it's time to get your voltage meter out and start checking things and checking all your connections to include grounds.

 

[KnotYet]

Just don't use your favorite screwdriver if trying the above!

Hint: this is one of the uses for the jumper cables I usually have aboard.

 

[kirkll]

Realistically... after reading the OP again, sounds more like a loose connection or possibly a corroded connection to me.

 

[Capt Dan]

Don't overlook the main ground wire where it attaches to the engine. This is a classic place for corrosion.

 

[Capt Ray]

Greetings,
Mr. PF. Do the simple cheap stuff first. Remove, clean and re-install ALL battery connections (High current draw) with appropriate anti-oxidant coating. Next do all other power (low current draw) connections the same.
Sounds like you have enough juice to energize the solenoids but not enough to turn the starter.

Do not forget the other end of those battery cables! The often hard to get to connections to the engine block and starter etc. are often the ones most ignored over the years. They deserve the same care as the battery end, and are often in a more aqueous part of the engine room than the battery bank.