Dr. Fred

My battery swich was left on all winter. The boat was stored in an unheated barn. The battery was completely dead. The boat jump started just fine. MOTOR is a 500EFI in a '01 Fountain 29.

On the way from the marina, I hit the trim tabs which killed the motor. Which is actually interesting because I was on the Niagara river, on the way to the falls. Fortunately the service guys came out and let me borrow their battery to get home.

It didn't take much encouragement to prod me into buying a new battery.

The new battery has 2 different sized posts, + bigger than-. Came with wing nuts too, making installation a snap.

The boat cranked and started great. When I hit the trim tabs, the battery voltage would dip to 10-11 volts and the green light on the halon system would get very dim. Actuating the Outdrive trim would drop it to 12 volts. All gauges would jump.

I spent last saturday upside down looking for a ground leak and couldn't find one. The only connection I couldn't check was the battery switch (couldn't figure out how to pull it.)

It finally occured to me that I couldn't tighten the (-) leads enough with the wing nut to secure the (3!) 2AWG ground wires.

After replacing the wing nut with a hex nut, the voltage drop is much better but it still exists. Tabs drop it to 12 volts instead of 10.

My question is:

Should I have bought a battery with a (-) post as big as the (+) post i.e., the same as original equipment? (To make a better fit with the ground wire)
(I thought I had bought original equipment, the names were virtually identical (seaworthy vs sea?) Amps and MCA were identical.


Does it matter what order the 3 ground wires get stacked?

Is this operation normal? Or will it be harmful? (Tansient voltage drop when k-planes are activated)

Should I look someplace else for a ground leak (any hints on common places?)

What would I do with an Ohm meter, if I were to buy one? (Where would I put the leads and what would it show if there was a ground leak?

Dr. Fred

wwwTOPDJcom

That quite normal for a battery to go dead during the winter
even with the switch off
you need to check the current being drawn off the battery
with the switch off and the ing off it should be below 50ma
thats with nothing running at all put meter between pos and the meter leads and just read it to see if there is any leaking
current
stacking grounds wont make much differance just larger gauge
wires first then the smaller they need to be clean and tight
so as to pass all the current through them

Turbojack

When your engine in running your alt. should be putting out aprox. 13.8 volts. when you put a volt meter on the battery. This voltage will change based on temp., load, & battery condition. Some time the gauge on the dash has a voltage drop problem or in incorrect but you should see aprox. a 2 volt difference between when the engine is running or off. On a fully charge battery after sitting for a while should have a voltage of 12.7 volts.

My guess is alt. is not working. Based on you voltages & the engine dieing with a low battery when you used the trim. If after checking voltage at battery with engine running & you see no increase need to pull alt. & have check. I usally take mine to a rebuilder & have them go thru it. This is cheaper that getting a new marine alt.

A battery will loose 10% of it's charge per month if just left to sit.

Hope this helps

Wally

iTrader: (1)

Also make sure all your common grounds dont have any corrosion. Not just at the battery but at any distibution blocks and on the engine its self!

BadDog

Doc,

You need to inspect the backside of the battery switch. I have seen these things full of the green. Hard to pass current through the switch if the wires attached are corroded.

Tim T.

MKast

Dr. Fred
You didn't mention if the new battery was charged or not.
If you think the negative is in question, use a good jumper cable to connect the negative battery post (with the negative cables still attached) to the engine block, like a bonding jumper. Make sure the contact on the block isn't painted. Start up, see if voltage drop is the same or reduced. The jumper cable will carry ground with the nagative cables.
If the drop is reduced, you'll have to address the issue.
Stacking cables shouldn't be a problem, you could alway install a negative buss to handle the stacking of cables.
Easy way to check for enough ground in the system.

FloridianSon

Just a thought when I did my pump motors I found that there is a week link in the wireing inside the pumps,the ground lead on the inside is split and they use a push me pull you connector (male-famale) so it can be taken apart,so on mine it had a lot of corrision and it did not work maybe this is causing more of a load than it should?

Dr. Fred

I did charge the battery again. Thought I overcharged it because it read almost 13 Volts. It's good to know the battery is not 12 volts.

I think the alternator on my boat puts out voltage in excess of 13.8. Its more like 14.6 and slightly higher if the battery is discharged.

My current plan is to disconnect the battery and cycle the on/off switch about 50 times.

I hope I don't have to look inside the trim tab motors.

Now the stupid question. Where do I put the black and red leads on the portable ohm/ amp meter to measure the battery discharge current with the battery and ?ignition switch off? Across the terminals? Or betwenn the positive and the engine block?

Dr. Fred

Turbojack

After charging a battery the voltage will be higher. Only after it sits for a while (maybe 1-2 hrs) or has a load put on it will the voltage start going down. The 12.7 volts is after battery has been sitting, not after just taking charger off.

To check voltage of battery leads go on each terminal of battery. If you put the red lead on the - post the reading you will get will be a - voltage instead of a + voltage. Both ways should give you the same number. (this is if you have a digital meter) To check AMP draw or current then meter needs to be between the battery post & the wires attached to it ( in series). Check your meter & make sure the meter is capable of doing this first before you do the current (amp) test. Checking current with wrong meter is good way to burn up a good meter.

When you are getting the 10-12 volts is this with the motor running? or motor off? Was this voltage taken from dash gauge. I have seen the dash gauge to be off quite a bit (1-3 volts)

FloridianSon

Just a thought on my elect. system I have four circuits one is my foward stero-lighting -bilge pump,ect and two on the starter one from the alt. one main engine-gages-starter solenid-circuit breaker,and one for my trim pumps.When looking for a draw or a short you should seperate the cicuits and check one at a time this will narrow down you search.You did not say if you have carb or fuel injection and I do not know if the computer has a full time draw on it like a radio would.Audiofin should know what the small draw would be on the radio even when it is off,re:memory still has small draw on it,not much but with normal winter sit time and a small draw from radio and if the computer has memory-full time small draw it could be a dead battery at the end of the winter.Bottom line if radio has small draw computer has small draw this will show up as a small load so they must be disconnect from the circuits when checking.Hope you find it or it is just normal draw and you did not disconnect battery for the winter.If there is a bad ground on the inside of the pumps it is only a problem when you go to use them, they will not cause a discharge of the battery but might show little more draw when they are used or just not work at all.Trim pumps can draw as much as 115 amps apeice under heavy load so if your battery was not fully charged when you hit them they just robbed the battery of all it had, ref;you jumped started it so it did not have the time to build back up and killed the ignition system.I was reading somewere it takes the average system on a car 17 miles of driveing to restore it to were it was before you hit the switch. James