8.2L runs then shuts off/won't start

[Metalcoat]

I have a 2013 chaparall 257ssx and a 8.2l mercruiser. Been running fine for the whole summer when yesterday we were out and the motor shut right off. Gave it a few minutes then it started fine and ran for another 30 mins then did the same. After a bunch of troubleshooting I noticed that the gauges wouldnt read and the engine shuts off when voltage drops to 0. The boat will not start until the gauges start reading something (13.9v).

A little disclaimer is I think I toasted one of the two batteries a few weeks ago leaving the radio on. I charged the battery back up but I don't think it's good. However I used the second battery to start the boat for the last few weeks and the boat started and ran fine.

If I turn the key the audio system makes a beep noise. However when the voltage is reading NODATA it doesn't beep at all. I checked the terminals on the battery and the electrical to the switch? And nothing is loose. Everything else electrical works fine, its almost like the engine isn't getting the power however it turns over fine just won't run.

Thanks

 

[alldodge]

I have a 2013 chaparall 257ssx and a 8.2l mercruiser. Been running fine for the whole summer when yesterday we were out and the motor shut right off. Gave it a few minutes then it started fine and ran for another 30 mins then did the same. After a bunch of troubleshooting I noticed that the gauges wouldnt read and the engine shuts off when voltage drops to 0. The boat will not start until the gauges start reading something (13.9v).

A little disclaimer is I think I toasted one of the two batteries a few weeks ago leaving the radio on. I charged the battery back up but I don't think it's good. However I used the second battery to start the boat for the last few weeks and the boat started and ran fine.

If I turn the key the audio system makes a beep noise. However when the voltage is reading NODATA it doesn't beep at all. I checked the terminals on the battery and the electrical to the switch? And nothing is loose. Everything else electrical works fine, its almost like the engine isn't getting the power however it turns over fine just won't run.

Thanks

Howdy

You have a bad connection somewhere or a battery is pulling things down. Start by load testing the batteries. If you don't have a load tester take it to a parts store and let them test it. Next check your battery cables, remove and clean, get bright shinny metal. Don't forget the negative cables and where it connects to the engine block.

 

[Metalcoat]

Would that kill the engine while running? I even get the problem when the batteries switch on both. I've checked all the connections I can see. I plan to go grab a battery today and just swap it out.

 

[alldodge]

Yes, if you loose 12V then the motor dies. It may be just coincidence that there was a battery problem along with your current issue, but both need to be checked out. With a display showing NO DATA means the computer is unable to communicate to the sensors (ie voltmeter). Your engine uses a CAN buss (555) to communicate with all systems.

 

[Metalcoat]

I appreciate the help. Where else could there be a loose connection? It can't be at the battery if I use the switch to go between batteries and they both have the same symptoms can it?

 

[alldodge]

I appreciate the help. Where else could there be a loose connection? It can't be at the battery if I use the switch to go between batteries and they both have the same symptoms can it?

The main engine harness connector, ECM connector, Main power relay might have a bad connection or is failing. just about any of the connectors including ones on the starter, main circuit breaker, alternator.

Could even be the CAN buss connectors.

You have two relays on the engine next to the ECM, they are both the same type. one is main power and the other is fuel pump. You could remove both, inspect contacts and swap them.

 

[Metalcoat]

I will inspect tomorrow morning. I will post back if I figure it out.

 

[Fun Times]

I appreciate the help. Where else could there be a loose connection? It can't be at the battery if I use the switch to go between batteries and they both have the same symptoms can it?

Bear in mind that if one battery is near dead and you had the battery switch on all then the good battery would be trying to recharge the bad battery meanwhile not allowing the engine to have the necessary power it needs to properly run the engine.

Also your engine model should have what is called "clean power" which is one of the main engine/ECM power lines that may be connected directly to a battery and not the battery switch...Should the clean power battery be the weak battery then the systems you mention are possible.

Google search "Mercruiser clean power" then be sure that power line is not going to the battery you use to listen to the radio all day long while at rest.

Is your engine digital throttle and shift that utilizes a command module mounted under the helm area? If so, it also has clean power going directly to a battery that needs to have full 12.6ish power at rest.

Your battery CCA (cold cranking amps) needs to be in the 800+ range.

 

[Metalcoat]

So I replaced the battery this morning. I am currently waiting for a tow. The voltage held for about 15 mins and started fluctuating and the engine cut but didn't shut off, ran for about 30 seconds then cut completely. I've narrowed this down to happen more as the engine compartment heats up.

I have little experience with engines etc, but I am usually able to resolve simple things myself. I noticed some people said it could be the coil or ignition switch.

The boat started fine this morning before I switch batteries as well. Any more insight is greatly appreciated.

 

[alldodge]

You have a loose connection somewhere, it will probably look fine but with some up close inspection and/or wiggling it should show up. If it was mine I would start with the ECM connectors, make sure to disconnect the battery before you disconnect

 

[Metalcoat]

Is there a diagram available online? My beautiful manufacture decided a CD was best.

 

[Metalcoat]

I can't find a bad connection.

 

[alldodge]

Manual 36 is for 555 has the wiring diagrams in it, but it is no longer on line. I'll try to make some jpg files and post later

 

[Metalcoat]

I've made some progress. The boat is out of the water now. I noticed on a large wave the seat over where the battery switch and cooler sit is slammed down and all of a sudden I get a beep from the gauges. I start up the boat and it does shortly after. I slam the seat down again to see if that does the same and sure enough it beeped and started fine so I moved back towards the dock and removed the boat. I now have the module where the switch is unscrewed but it won't pull out much further. There is a bep dvsr voltage sense relay located there and when I had the batteries connected it blinked fast red when I turned the switch to both or 1 or 2. Could that relay be bad?

 

[alldodge]

bep dvsr voltage sense relay

A DVSR relay is a Digital Voltage Sensing Relay is used to combine two batteries together once the engine is running so the one ALT can charge both batteries. Your moving your Bat switch (1, 2 Both) but this does not need to be done because the DVSR does it automatically. Your switch should only be needed if the boat won't start on Bat 1 or 2 (which ever you use for the start side. With the beep going on I would say you might just have found a bad connection on a contact or terminal.

 

[alldodge]

Put together some pages

 

[alldodge]

A bot more

 

[Fun Times]

Metalcoat may have an PCM-09 (Propulsion Control Module) ECM design, if so, chances are low there being any wiring diagrams or service manuals available online.

MerCruiser introduced the PCM-09 ECM module on their 2009 model year engine's equipped with catalytic converters. These engines are initially intended for the California market and are designed to meet OBD-M emission requirements.
The PCM-09 module is an entirely new ECM type for MerCruiser and bears little resemblance both physically and functionally to the PCM-555 / ECM-555 modules used on their non-catalyst engines.

If anyone is interested, see page 49 for the design of the PCM. TechMate marine v6 for pdf - Rinda Technologies Inc ...

 

[Metalcoat]

I got so frustrated with that connection where the switch is. I can't remove the base plate. I know that if I spend more and more time I would have yanked it out and broke more. I dropped it off to the local merc shop and left a detailed message of where I think the short is.

I will post back tomorrow after work and see what they say. This forum is great!