94 evinrude 112hp voltage drop when cranking

[tbull]

I thought I may have just had too many things running off 1 battery, so I now have 2 batteries running everything on the boat. The problem is that when I crank the engine, the voltmeter gauge on the dash drops from just over 12 volts down to 8 volts during the crank. I did a rectifier test and a voltage drop test according to the manual, what else could be causing this? Thanks

 

[cdoliver]

Re: 94 evinrude 112hp voltage drop when cranking

Check your battery connections.They need to be clean and shiny. Otherwise a voltage drop is normal.

 

[R.Johnson]

Re: 94 evinrude 112hp voltage drop when cranking

It almost hast to be to much starter draw. Are the battery contacts' clean, and tight? Are you using wing nuts on the battery contacts?

 

[tbull]

Re: 94 evinrude 112hp voltage drop when cranking

Wing nuts, the connections are shiny and clean. I recentley re-did every connection to the battery because they were looking rough. Also had battery load tested, every test has passed.

 

[R.Johnson]

Re: 94 evinrude 112hp voltage drop when cranking

That puts you back to the starter.

 

[tbull]

Re: 94 evinrude 112hp voltage drop when cranking

Do you think its the starter itself or the connections to the starter?

 

[F_R]

Re: 94 evinrude 112hp voltage drop when cranking

You didn't say whether or not the starter cranks. If it does, and it is just a low reading on the voltmeter, you may have a high resistance in the wire between the motor and ignition switch. How many volts do you have at the starter cable nut?

 

[tbull]

Re: 94 evinrude 112hp voltage drop when cranking

Sorry yes the engine does crank, but at night all the lights dim on every crank, and it has gotten to where it sucked the battery dead. If you mean the positive terminal on the starter? I have checked that and have 12.5 volts, again it cranks, I just dont see why I should loose that much voltage, especially when the boat is running on 2 fully charged batteries???

 

[R.Johnson]

Re: 94 evinrude 112hp voltage drop when cranking

I think it is the starter, but if we don't talk about it, I think it will go away. What do you think?

 

[F_R]

Re: 94 evinrude 112hp voltage drop when cranking

So you are telling me you have 12.5 volts on the starter and only 8 volts on the dash meter? If you have that much on the starter, you have very good batteries and cables and negligable voltage drop in the cranking circuit. Your voltage drop must be in the wire feeding the ignition switch and voltmeter. Do you have your lights connected to that wire too? Something doesn't compute here.

 

[R.Johnson]

Re: 94 evinrude 112hp voltage drop when cranking

You should have about a 3 volt drop when cranking, if you had a battery ignition, that would be about the breaking point for the engine to start.

 

[tbull]

Re: 94 evinrude 112hp voltage drop when cranking

I am not sure if the lights are on that circuit or not. When I bought this boat it was an electrical nightmare, its almost like every gauge or wire under the dash are wired together and going to a fuse panel. If its a voltage drop in the starting circuit, how to I troubleshoot that and track it down. Your right it would almost seem like the lights run on the same circuit. The guy I bought it from had everything and I mean everything running on 1 battery, and its not a very small boat 19.5 ft. Where should I begin?

 

[tbull]

Re: 94 evinrude 112hp voltage drop when cranking

Also, the voltage drops to 8 during cranking, when not cranking it will show the 12 volts, the starter is getting the 12+ volts with or without the crank.

 

[Outsider]

Re: 94 evinrude 112hp voltage drop when cranking

Barring any unusual equipment, a single charged battery of sufficient size should carry the entire electrical load under normal circumstances. If you're getting this much voltage drop with two batts in parallel, you've got a major amp draw in the ignition circuit. I, too, would begin at the starter and work from there ...

 

[F_R]

Re: 94 evinrude 112hp voltage drop when cranking

Also, the voltage drops to 8 during cranking, when not cranking it will show the 12 volts, the starter is getting the 12+ volts with or without the crank.

That is totally impossible. If there were 12 volts at the starter, it would be cranking. Or burned up and wouldn't crank at all.

EDIT: Disconnect the motor's battery cables from the battery, leaving everything else connected. Do your lights still work? If they do, they are not wired to the motor. Nor should they be.