GNJ

Over the weekend a hose burst on the raw water pump and sprayed down the side of the motor where the starter is. Limped back on the other engine. Next day, could not get the engine hatch to come up. The hydraulic ram cylinder that opens the engine hatch is acting weak and only getting slight voltage. When I connect the battery straight to it, it raises and lowers no problem.
Smelled a burn smell and noticed the starter burned up and so I removed it.
When I turn the ignition key on, the volt gauge reads only 11 volts and the initial sound the alarm makes is weak compared to the other engine. I tested the batteries and both seem fine with 12.27 volts.

Anybody help me where to look?

SpeedDemon641

Check the battery cables sometimes they will get sulfated inside the insulation if you,ve never changed them probably a good idea to replace them while the starter is off. Also check your ground cable and wires as well if they aren't getting a good connection that could cause it. And make sure its a marine starter and not a regular automotive starter that could be the problemas well. Just my opinion.

Wobble

I agree, sounds like a ground issue. Also check the main harness plug while you are digging, check all the pins and go back with di-electric grease.

GNJ

Thanks everyone for your suggestions! Well I checked and cleaned the ground to the back of the motor and to the batteries. Battery cables check out as well. Also, checked the engine pin connector and all that looked really good. Checked the battery switches and all that is good. Installed a new mercruiser starter. I have 12.27 volts at the ignition switch. When I turn the key to run position, I only have 11 volts on the leg that goes to the ignition. The other motor I compared to has the same voltage on both legs in the run position.
When I turn to the start position the voltage drops to 8 volts and it sounds like the starter solenoid circuit starts to engage but then the whole circuit quickly goes dead. Turn the key back to off and then back on and power is back and the same thing happens all over again, turning the key to run and then start. Seems like something is draining the power in the run position and then cutting out the power completely in the start position after 1 second.
I'm really stuck here........ Any other ideas?

SpeedDemon641

If you checked all the wiring and nothing is melted or corroded try swapping the good ignition switch onto side giving the trouble it could be the switch. Before that though try running a temporary ground wire directly to the starter housing where it mounts to the block. If the starter isn't getting a really good ground it will cause what your describing. Check to make sure where the starter mounts to the block isn't rusted and corroded. Also just to be totally sure try swapping the batteries around I have not found a marine battery that last more than about 2 years. Did you bench test the new starter before installing I have seen starters be bad out the box.

GNJ

OK figured it out. Can't believe I missed this. It was as simple as the 50 amp circuit breaker that was tripped, which must have happened after the starter burned up. Thank your SpeedDemon and Wobble for your help. Volt guage went to 12 volts and motor started right! Yeah!

dereknkathy

that means you have something else hooked up wrong supplying batt voltage around the 50 amp breaker. or wire insulators melted and let 2 wires cross-connect with same result. when breaker pops system is sposed to be dead dead dead...

Wobble

I think you will still have power on the purple ign wire. Not 100% sure as there are many variations.