2000 7.4 Mercruiser wouldn't crank

[German Vergara]

Hello to everybody I've been getting information from this forum since I became a member about 7 months ago but I never had to ask a question before. I purchased my used 1999 Sea Ray 270 Sundancer in January of this year, its my 1st cabin cruiser i've owned a 26' sailboat, a 22' deck boat and still own a 19' skeeter bass boat.I purchased the Sundancer because it had a new 2000 7.4 (454)Mercruiser engine with a bravo III that had a 1 year warranty. I'm trying to give as much info about me and some of the knowledge I have in boats.
The problem I have is:
My engine will not crank, the batteries are recharged and are about 6 months old, I have tried the following
1.Start the engine and made sure is in neutral.
2.Used my other 2 batteries from my battery bank that I have fully charged on the boat,also newer.
3.Checked the circuit breaker ( I don't know how hard i have to push in and release but i did as far as i could without braking it.
4.Replace the ignition slave solenoid.
5.Replaced starter with a new one (hard job to do, not much work area to do it but. got it done)
After doing all of the above the engine still doesn't crank.
I turn ignition switch to start, alarm goes on as normal and goes off, I hear hissing from fuel pump as usual and then all I hear is a click .Please help! I always try to do all of my mechanic work on my boats but I've been trying to fix this on my days off for the last 3 weeks.

 

[scoflaw]

Got 12volts on the r/p at the slave? If yes, will it crank by jumping the 2 large terminals at the slave? You need 12v. on the small y/r wire at the slave when the key is turned to start. Need a ground there also. Got a good ground connection from the battery to the back of the block?

 

[kap2]

You may want to try to turn the engine over by putting a socket and ratchet on the front of the crank shaft and give it a spin to ensure its not hydro locked.

 

[German Vergara]

Hi. Thank you for your prompt response guys. I can't work on the boat during the week, always working. I tried what Scoflaw advised to do by jumping the 2 terminals at the slave ( with the ignition on) and nothing happened, the engine did not crank either, I do not have a volt meter to check if I'm getting 12 volts there, maybe I should get one. I also tried turning the crank shaft as advised by kap2, correct me if I'm wrong , I put the socket at center of center pully? At lowest part of motor, With 19 mm socket and tried turning it but I couldn't make it turn either way. What steps do you guy think I should I take now?

 

[Espos4]

What steps do you guy think I should I take now?

Get a volt meter or hire a mechanic.

I'm not being sarcastic, but you need to know if you have power and ground at the appropriate spots before this can be further diagnosed.

 

[German Vergara]

Ok I'll get a volt meter and check tomorrow,thank you.

 

[Chris-380]

Ok I'll get a volt meter and check tomorrow,thank you.

You should of seen a spark when you jumped across the relay. Especially if it was locked up

 

[German Vergara]

Ok guys thank you again for responding so quickly. So I got a volt meter and checked volts at battery, hood 12volts, I then tried at slave solenoid, with ignition switch on, and no voltage, what next please.

 

[German Vergara]

To Chris-380. I did not have a spark as you pointed out

 

[scoflaw]

Check voltage on both sides of the 50 amp breaker near the slave

 

[German Vergara]

Check voltage on both sides of the 50 amp breaker near the slave

I checked but nothing 0

 

[scoflaw]

The 50 amp breaker gets power from the 90 amp fuse on the starter, red wire.

 

[German Vergara]

The 50 amp breaker gets power from the 90 amp fuse on the starter, red wire.

OK, I don't want to sound clueless but I am, what should I check then?

 

[scoflaw]

Power at the 90 amp fuse on the starter. If it looks like a ball of rust, clean all the connections real good.

 

[German Vergara]

1 of the things I did before I tried to get help from you guys was replaced the starter with a new one :"The problem I have is:
My engine will not crank, the batteries are recharged and are about 6 months old, I have tried the following
1.Start the engine and made sure is in neutral.
2.Used my other 2 batteries from my battery bank that I have fully charged on the boat,also newer.
3.Checked the circuit breaker ( I don't know how hard i have topush in and release but i did as far as i could without braking it.
4.Replace the ignition slave solenoid.
5.Replaced starter with a new one (hard job to do, not much workarea to do it but. got it done)
After doing all of the above the engine still doesn't crank.
I turn ignition switch to start, alarm goes on as normal and goes off, I hear hissing from fuel pump as usual and then all I hear is a click .Please help! I always try to do all of mymechanic work on my boats but I've been trying to fix this on my days off for the last 3 weeks".

 

[German Vergara]

All connections were clean when I replaced starter

 

[scoflaw]

The battery+ cable goes to the starter and connects directly to the square 90 amp fuse. The other end of the fuse has a few wires attached to it, one of them being the red wire that goes to the 50 amp fuse.

So if you have no power to the 50 breaker figure out where your losing it.

 

[German Vergara]

Yes the 90 amp fuse is new and on starter, so I have to trace back from starter to battery switch?

 

[scoflaw]

I would assume your battery switch is on. Do you have power at the 90 where those wires attach to it?
Maybe you forgot to attach the red wire that feeds the 50 amp breaker.

 

[German Vergara]

Scoflaw and all you guys thanks gor the help. While tracing wires back from starter I found the mistake I made, I connected the cables wrong on the starter stupid me, once I connected them the right way it started right away, again thank you very much for all your help.