Mercruier 170 Battery Issues

[Newguy1330]

I have 21ft Larson with a mercrusier 170 on it. Have not and any battery issues all year. Boat has already started right up on land and water. Took it out the first time today and cruised out about 1/2 mile from shore. Turned the motor off and left the radio on and the blower on on accident. 45 min later we go to leave and the batteries are both dead. Get it jumped and started heading in. Go to stop for a sail boat and put it in neutral and the boat stalls and battery is dead again. Any ideas!? Will both batteries died that fast?

 

[Bt Doctur]

the battery switch should never be on both unless coming or going. The batteries are toast or the stator charging system is bad

 

[Newguy1330]

Ah ok. Would that cause an issue then since we did leave it on both? The batteries are both less then 2 years old

 

[Bt Doctur]

With the switch on "both" a bad battery will take down a good battery . What does the voltmeter gauge read when running or does it have a ammeter gauge?
Do you know how to use a voltmeter to test? Has it been converted to a standard alt system?

 

[Newguy1330]

The volt meter on the dash was at 8 - 12 I believe but I'm not sure how accurate it is. My plan is to go out today and huy a separate one that will read both batteries. No im not sure how to do that test and nothing has been converted.

 

[Bt Doctur]

sounds like a charging problem then . that system does not like to charge up dead batteries so lets hope its not cooked. with fully charged batteries read the voltage at the battery.
Start the engine and go to 1500 rpm. Voltage should increase above the initial battery voltage reading

 

[Bt Doctur]

Basically the yellow/red from the stator is AC voltage into the regulator .around 30 volts .There are tests for grounds and shorts.
The Purple/Red is DC output 13.6 on average
If you cant find manual 8 I can burn it or use this link to view and print pages http://boatinfo.no/lib/library.html

 

[Newguy1330]

Ok. Is that system pretty easy to replace? I'll pull the batteries out today and get the fully charged and and checked and then test them.

 

[Bt Doctur]

Ok. Is that system pretty easy to replace ,if replacement parts were availabel and reasonable
Some have used the harley motorcycle electronic regulators with some succes .Think they were rated at 30 amps

 

[Newguy1330]

I dropped off the battlers to be charged and tested. 1 tested at 0 CCA the other was at 269 CCA out of 680. They are going to keep them for the night and see what they come in at tomorrow.

I did notice that when I was taking them out I put the. battery switch on the individual batteries are tried starting it. 1 almost started the boat. The other didn't give me a click or anything. Is that due to the CCA being down or another issue.

 

[Bt Doctur]

Most likely Yes..Trying to start that engine with a weak or dead battery and a jump kills the charging system. If the batteries are 3 or more years old, replace them.

 

[Newguy1330]

Do you by chance have the proper way to run a dual battery system? I'm going to double check that and also replace the wiring. Some seem to be in bad shape.

I have been looking for a conversion kit but not having any luck.

 

[Bt Doctur]

Red wire from engine to "C" common, Red wire from battery #1 to "1" on battery switch, Red wire from battery 2 to #2 on switch., neg post to neg post and engine neg wire all together

 

[nola mike]

Breezeworks.net has the conversion kits. BT, I don't remember ever seeing anything about HD regulators?

 

[Bt Doctur]

Its been kept quiet. HD uses the similar rotor/stator setup. The big Harleys went to a 3 phase for more power THe FX/FD are 2 wire stators This is a 32 Amp unit

 

[QBhoy]

Is this the 470 in line 4 engine ?
If so, if it's not defo battery related....I will take a guess at the old water pump then overheating, causing the head to warp and let water in to hydraulic lock issue ?
Perhaps the extra boost from the jump start was enough to turn you over to a spot where it could start ?