Could weak battery cause this...

[Chexi]

Okay, so as some of you may know, I have had a weird problem with my new to me 2000 SAN with GT-40. It happened again today, so that's 2 for 2.

Symptoms:

1. Boat appears to run fine for about 1-1.5 hours. Then it will start to stall at idle. Today, same thing. Fine when starting out, but about an hour in, the same thing happened. Today I noticed that the engine light came on when the problem started. Intermittent at first, but once it starts, the frequency of it happening increases.

I changed both the fuel and the other relay before going out today, but that did not fix the problem.

Other things I noticed, the volt gauge was showing 15 volts when the problem first occurred (which seems high to me).

When I pulled the boat in and stowed it, I noticed that my CTEK comfort indicator was showing amber (meaning not fully charged battery). I hooked it up to my charger and it showed not really weak, but not fully charged. On my old boat, after coming in, I was always green/fully charged. (Note, I did not play the stereo at all today. I did have my GPS hooked up to a 12v plug).

Also, my v-drive warning light stayed on the entire time (and as a result we took it very easy and were only out about 1.5 hours). I checked the v-drive oil fairly early into the day and it was actually high. The dealer I bought it from (not a nautique dealer) probably over-filled it. I'm not sure if too much oil in there will cause the light to come on or not. I suspect I need to suck some out.

However, I was wondering if maybe my battery is weak, and maybe it is causing this problem. It seems like it would cause it from the get-go, and not after the engine warms up, but I know that a weak battery can cause weird problems. Anyone have any ideas or had a weak battery cause similar symptoms? Also, anyone know if too much oil in the v-drive would cause the v-drive light to stay on? Thanks.

I do plan to take it to a dealer on Monday to get checked out, but thought I would check with the PN brain too. Thanks.

[WakeSlayer]

I would pull the battery and get it load tested at a shop. Sounds bad to me. Your V-drive light is a temperature alarm if I am not mistaken. It is a very low pressure system. Get the level right and see what it does. Could be a bad sensor, I have heard of that once or twice.

[bchesley]

Scott,

Sorry I did not get your message until late last night. We were out on the water late and my phone was in the bottom of my back pack. The guys as Ski and Sport were probably long gone when you called. Matt, who you usually talk to was not there either. His dad passed away and he has been gone all week. I would call them on tuesday to line something up.

The light on the Vdrive is a pressure switch so it staying on with fluid in it tells me the sending unit is bad. As for the battery issue, I am not sure that a weak battery could cause those issues. I am under the impression that the boat runs off the alternator and the battery just starts the boat. I could be wrong though. Maybe a bad ground wire? Sometimes a bad ground on the block can show up after the block heats up and expands a little.

[Chexi]

No worries. It was a long shot. I may have to call the other dealer though since Ski N Sport is still on winter hours and not open on Monday (and with Matt's dad and all). I'm sorry to hear about that.

[Chexi]

Pre-diagnosis, but based on my symptoms one dealer is thinking I need a new fuel filter. Another is thinking possibly a bad battery causing weird electrical problems. We shall see.

[xrichard]

I'm thinking a bad alternator is more likely than a bad battery. If you leave your battery on charger, then it's topped off at the start of your outing. If your alternator isn't putting out, your boat is running off the battery...after a couple of hours, your battery is low and your boat starts acting up. Eventually, it won't run. When you get home, you'll have a battery that's drained down.

I wouldn't rely on the voltage readings at the dash--test with a multimeter at the battery. A quick and dirty test for your alternator: check your battery voltage with the engine off...if fully charged, it'll be 12.6-12.7 volts. Then start the boat and test across the battery again...it should read 14.5-15 volts (which is the voltage from the alternator).

[Chexi]

I hope it is a bad alternator. I have the 100 amp upgraded alternator just waiting to be installed. Boat is at the dealer now, so hopefully they will have an answer soon. I will post when I learn more.

[IMPACT-EV1]

I'm thinking a bad alternator is more likely than a bad battery. ...it should read 14.5-15 volts (which is the voltage from the alternator).

I agree that it's most likely a alternator issue but the 14.5-15 volts is a bit high and will boil most batteries and render them to a pile of junk due to over charging.

[xrichard]

It'll come down quickly because of the voltage regulator...and 15v is too high...but +/-14.5 immediately following start up is where it should be. The specific voltage isn't important for doing a quick test...the important part is seeing voltage in that range. FWIW, the alternator on my Expedition went bad...the new one puts out 14.7v on start up and then comes down after the battery takes the initial charge to replace the draw from starting.

[IMPACT-EV1]

It'll come down quickly because of the voltage regulator...and 15v is too high...but +/-14.5 immediately following start up is where it should be. The specific voltage isn't important for doing a quick test...the important part is seeing voltage in that range. FWIW, the alternator on my Expedition went bad...the new one puts out 14.7v on start up and then comes down after the battery takes the initial charge to replace the draw from starting.

I'm well aware of the inner workings of a alternator and what all of the pieces internally do and don't due, developed one or two for Delco-Remy back in the day.