Could no alternator cause these problems?

[jakehorton15]

Goodmorning everyone, for about half the summer we've been having some issues with our boat. It's a 1994 bryant 180 with a 4.3lx 4bbl. The boat will run great for the first day or so at the lake and then at higher speeds after a couple days it will kind of start to lose power and have a difficult time maintaining a steady speed and kind of surges like it wants to go but can't. I kept thinking it was a fuel issue and checked all the fuel delivery and changed fuel water filter and checked anti siphon valve and all was good. Im rebuilding carb this week just because it's time to be done anyways. But I tested my battery with the multimeter the other day with the motor running and at 2000 rpm and was only ready 12.5 volts. So I assumed my alternator was dead but got down there to remove it and found the main power wire on the alternator the ring terminal had rusted and completely broken off. And hooked it back up with a new ring and the battery is reading 14.4 at idle. So all is well now. I was wondering could the fact I was only running on battery power all weekend cause that power loss? I have 2 batteries wired together but have 2 500 watt amps for subs and tower speakers. We would notice a real surge in power anytime we would operate the trim and tilt while under way. If anybody has any ideas Id love to hear them. Thanks!

 

[bruceb58]

That definitely could have been your problem.

 

[gm280]

I would agree with bruceb58. ^ 1

 

[NHGuy]

You fixed it man.. Now rock out!

 

[bruceb58]

I would be checking all the wires down at the starter and clean them with sand paper until they are shiny. The fact that it surges with trim applied shows there is a low voltage condition. I think there is a combination of things happening which cause low voltage to be sent to the ignition circuit.

 

[skippy2235]

Then after you get them all shiny, spray some electrical spray and then spray a heavy coat of good quality paint on them. to keep them covered and rust free.
Short term fix but helps

 

[Bondo]

Then after you get them all shiny, spray some electrical spray and then spray a heavy coat of good quality paint on them. to keep them covered and rust free.
Short term fix but helps

Ayuh,.... Or just slather 'em with Grease,......

 

[thumpar]

HAHA Of course you use grease.

 

[skippy2235]

Yea but grease gets on everything, and is messy.

 

[gdpalumbo]

If all that was running off your battery was your motor I'd say two parallel batteries would be more thaN enough to run the ignition on that engine for quite a while. That said, two 500 watt amplifiers will draw and enormous amount of current off your batteries. Lets assume that without an amplifier a 500 watt speaker at 16 ohm is drawing 5.5 amps of current off your battery every time it hits. This is not an accurate description of your amplified setup as a lot goes on in amplifier that will change that current draw. Now, if that 5.5 amp speaker is connected to your boat battery that has a reserve capacity around 150 or so and is basically say a 75 ampere hour battery, that battery can handle 1.25 amps of load per minute for 60 minutes or 75 amps for one hour. Hope this gives you an idea of how much power consumption goes on when you run those speakers and your engine together so I believe you have solved your issue of your alternator not supplying the 40 amps+ of charging current to your batteries ( that's if it's similar to a car alternator) i'm not sure what the charge current rating is one that motor.