Need help please! Boat won't start.

[csleaver]

Loose or corroded connections between the battery and starter can cause voltage drop.

[jjackkrash]

5 hours ago, GX2 said:

Put the multi meter on the power post at the starter, and turned the ignition to the ON position and got 10.69?

10.69 volts resting is below fully discharged.  12 volt starter batteries should be around 12.6 volts resting when fully charged.  

[oldjeep]

7 hours ago, csleaver said:

Loose or corroded connections between the battery and starter can cause voltage drop.

Which is a good reason to also check voltage at the battery terminals.

[justgary]

7 hours ago, jjackkrash said:

10.69 volts resting is below fully discharged.  12 volt starter batteries should be around 12.6 volts resting when fully charged.  

And closer to 13.8v if it was recently charged.

[GX2]

Alright, put the charger on one of the batteries last night before going to sleep. Came out to the garage this morning and charger said fully charged. So I tried to start it. No luck. 

I put the meter on the starter power wire with the Ignition in the ON position and got 11. It was at 10.69 yesterday.

Put the charger on the other battery and waited a couple hours until it read charged. Tried to start it again, and nothing. 

Power post on the charger is still reading 11 with both batteries completely charged. 

Next, I might try jumping the batteries with my truck to see if it will start. Not sure what else to do.

[GX2]

11 hours ago, csleaver said:

Loose or corroded connections between the battery and starter can cause voltage drop.

As I've been trouble shooting this problem. Everywhere I took a wire off I made sure to sand down and tighten for good connection.

[GX2]

3 hours ago, oldjeep said:

Which is a good reason to also check voltage at the battery terminals.

Will do this next too.

[GX2]

Quick question. When turning the ignition on, the dash gauges will begin to work. I show the battery and fuel gauges respond. But does the oil pressure gauge stay at zero?

[wdr]

Yes until the pump spins to generate oil pressure. 

[GX2]

Both batteries are reading 12.88 and 12.78 at the their posts.

[GX2]

Just put a jumper from the starter power post to the smaller solenoid post with the ignition switch turned to ON. I got the starter to kick on and try to turn the engine over.

So I don't think the engine is hydro locked. Now will continue to work backwards. 

[GX2]

Checked the volts on the ignition switch in the start position and it read 12.43. So it's sending power, but somewhere between there and the starter it's getting cut off. I looked at the breaker below the dash and it is not popped. 

Anyone else know if there is another fuse/breaker/relay in between the ignition switch and starter?

[GX2]

Okay, as I'm investigating and working my way back from the starter to figure out what is wrong. I was following the yellow wire with red stripe from the starter solenoid back by the ECM. 

After looking very carefully I noticed something that looks to be like a starter relay? Similar to one that you would find on an older truck that is mounted to the side of the truck. 

Did anyone know this was there? And is this really a starter relay?

This might be the root cause of my problem. I hope....

[GX2]

Also, does anyone know how I get to it to test and replace it?

[justgary]

Photos? 

[oldjeep]

8 hours ago, GX2 said:

Okay, as I'm investigating and working my way back from the starter to figure out what is wrong. I was following the yellow wire with red stripe from the starter solenoid back by the ECM. 

After looking very carefully I noticed something that looks to be like a starter relay? Similar to one that you would find on an older truck that is mounted to the side of the truck. 

Did anyone know this was there? And is this really a starter relay?

This might be the root cause of my problem. I hope....

You talking about an external starter solenoid like this?  

 

[formulaben]

On 6/9/2021 at 7:29 PM, oldjeep said:

10.69 seems pretty low - basically dead.

What does you battery voltage read at the posts?

 

On 6/9/2021 at 9:50 PM, GX2 said:

I thought 10.69 was low too. But the batteries are literally brand new. Bought them today.

 

On 6/9/2021 at 10:31 PM, csleaver said:

Loose or corroded connections between the battery and starter can cause voltage drop.

 

22 hours ago, GX2 said:

As I've been trouble shooting this problem. Everywhere I took a wire off I made sure to sand down and tighten for good connection.

Where is everywhere?  I'm certain you have a conductivity problem, so I'll ask if you removed ALL connections, both red AND black?  You've got the following connections to remove, clean, and tighten:

• Positive on starter
• Negative on engine block
• Positive(s) on master switch, incoming
• Positive on master switch, outgoing
• Positive on battery 1
• Positive on battery 2
• Negative on battery 1
• Negative on battery 2
• Any intermediate connections, such as ACR or bus bar connections

You've established the voltage is good at the batteries, so it is somewhere downstream from there...you didn't mention what type or if a master switch is installed, or if you have a charging relay or not.  If you do have a master switch, check the incoming voltage.  First use the battery negative terminal(s) to check voltage, then use the engine block.  You'll be able to isolate where the fault is from there.

Do you have a master switch?  It could be a bad switch...I'd cycle it several times and see if anything changes.

Also, this assumes the cables are healthy and there is no corrosion at the terminal ends...are they crimped or soldered?  How do they look?