Low Voltage?? PLEASE HELP!!

[wakeman777]

Alright I have had a Low Voltage come up. Had Dealer Look at Alternator and they said it is running fine; however, when I run about 30mph, with it on both batteries, and have Stereo running(Factor Set-Up) the Volts are going way down and Low Voltage keeps poping up. Then if I stop the boat, there is nothing to crank the boat to start. Have to re-enter Code to try again, and then it is real sluggish...
Could Dealer be wrong about Alternator?
Could both batterries be bad?
What is the Problem???
By the way it is an 2006 SAN 210 TE. Please HELP!!!

[CradGen2]

RE: Low Voltage?? PLEASE HELP!!

Could have a belt slipping or bad regulator on the Atlernator. Also might have a short in the wiring somewhere. Just my guess.

[DanielC]

RE: Low Voltage?? PLEASE HELP!!

How did the dealer check it? Did he just start it, and then check the voltage without turning all the accessories on?
there is an "Old School" piece of equipment that is around many auto shops. I think it is a Sun VAT-20. It has a volt meter, and an ammeter, and most importantly, a carbon pile you can use to apply a variable short across the battery.
Once the device is hooked up, and the engine is running, (with cooling water supplied to the raw water pump) you start to load down the alternator with the carbon pile, checking the amp draw, and supplied voltage.
If the alternator does not supply it's rated amp output, and maintain the 12 volts, the alternator is weak.
If the alternator can maintain the rated amp output, and voltage, your batteries might be going bad.

[hyperwake]

RE: Low Voltage?? PLEASE HELP!!

I had a similar issue most of the season last year. Took me till the last time out to figure out that BOTH batteries were bad.

[JUST-IN-TIME]

RE: Low Voltage?? PLEASE HELP!!

sounds like batts

[kaikane]

RE: Low Voltage?? PLEASE HELP!!

You most likely have a few dead cells in your battery bank. Suggest you get a 12volt load tester and 'load' test the batteries after fully charging them. If the battery can't handle the load, then you have a dead cell. Dead cells can wreak havoc on a 12volt electrical system, and if not taken care of promptly, can cause premature failure of your alternator.

Think of it like this, a dead cell in a battery is like the houseguest who never goes home...they eat all your food, drink all your beer, hog the TV remote and you keep giving them all of the above 'hoping' they will go away eventually...but they never do until you kick them out!

Go get yourself some new batteries!

[Rick]

RE: Low Voltage?? PLEASE HELP!!

Any Auto store will test your Batteries for free. Take them out, charge them and take them in . It takes about 5 min. per.

[HS]

Re: Low Voltage?? PLEASE HELP!!

when I run about 30mph, with it on both batteries,

Shouldn't you run on one battery and keep the other one off? (I switch between batteries every time I go out.)