Dead Batteries? Bad Alternator? Not Charging?

[lmannyr]

I have a 1989 220 Sundancer Single Engine Merc replaced in 2000 with a 2000 block, aluminum heads, holly carb.

Bought the boat about a month ago. Yesterday was my 3rd time out with my baby. Other than the initial dead batteries at the ramp, the boat has been running flawlessly.

I replaced what looked to be the original battery switch by Guest, with a Blue Sea switch with alternator disconnect. The alternator disconnect was not wired in since I don't know how to wire it in and the original did not have this feature (future upgrade?).

I always run the engines on muffs before leaving home. 1st time out no problem. 2nd time out, I noticed the engine starting a bit slower. 3rd time at home on muffs, engine started right away.

The 3rd time out was just like the others. Run on muffs, get to gas station and flip on the blower, gas up, flip off the blower, arrive at staging area, flip on blower, get to ramp while on trailer starter just clicked away. Both batteries, same problem.

One of my batteries had a broken post so I always ran it off of the starboard
battery.

What caused this? I don't remember if I tried starting on the broken battery or not but did not try the other switch position to not hold up the ramp.

I pulled out headed to the nearest auto store and bought 1 exact battery to replace the broken post battery.

Engine started right up!

Today I grabbed my trusty Fluke Multimeter and this is what I gathered.

engine off and negatives off...

Port Batt 12.55V
Starboard Batt 12.69V

Engine on negatives back on...

Switch to port 14.36V
Swtich to starboard 13.93

New battery is in starboard side.

Do the numbers look right?

Thanks

 

[lmannyr]

Re: Dead Batteries? Bad Alternator? Not Charging?

OK....I out of curiousity, and for hard evidence, I just went out and started the engine in the 1 & 2 positions without problems. Wonder if I tried using the broken battery at the ramp?

I got a replacement out of this incident. How do the numbers look?

Thanks Again

 

[chiefalen]

Re: Dead Batteries? Bad Alternator? Not Charging?

If it were my boat. I would have a simple cutoff at the battery, on/off one battery.

The new one hooked up.

The old one on board if you need a anchor.

Old battery could be drawing down the new battery.

Take alternator to auto store let them test it free.

If good, great if bad you need a new alternator. Marine please.

I don't want to read about you blowing up.

 

[achris]

Re: Dead Batteries? Bad Alternator? Not Charging?

engine off and negatives off...

Port Batt 12.55V
Starboard Batt 12.69V

Engine on negatives back on...

Switch to port 14.36V
Swtich to starboard 13.93

New battery is in starboard side.

Do the numbers look right?

Thanks

First question... Why are you switching negatives?

The voltage on the port battery looks good, but I suspect you have some resistance (dirty or loose connection) in the circuit between the alternator and the starboard battery, or the battery was low in charge.

The alternator output on a fully charged battery should be between 14.2 and 14.8 volts, which you have.... So, your alternator looks good...

Chris........

 

[lmannyr]

Re: Dead Batteries? Bad Alternator? Not Charging?

First question... Why are you switching negatives?

I disconnected the negatives while engine was off and switch was off to make sure nothing was drawing current, dropping the voltage. The negatives were not switched.

I rewired the switch today. I noticed a lot of stuff (ignition, trim, macerator and two unknowns) connected directly to the starboard battery. 2 unknown wires were left disconnected until I find something that does not work. Everything is on the switch now. When the switch is off, NOTHING WORKS!!! Exactly how I want it. I trailer so I'm not worried about the bilge pumps, my plug is always out.

Where does the alternator charge the batteries. Where is the wire usually connected?

Thanks!!!

 

[achris]

Re: Dead Batteries? Bad Alternator? Not Charging?

I have a 1989 220 Sundancer Single Engine Merc replaced in 2000 with a 2000 block, aluminum heads, holly carb. ....

Unless you are running a closed cooling system, this is really bad... The salt water is going to eat those heads VERY quickly.... Start looking around for some cast iron ones to replace them....

The output wire from the alternator goes to the main post on the starter solenoid. Same post the main battery cable is on... That's why you should NEVER switch the battery switch OFF while the engine is running... If you do, the alternator sees nothing and sends the output voltage through the roof, blowing ever piece of electrics on the engine, and usually the alternator itself too (the internal regulator)

Sorry about the 'switching negatives' comment, misunderstood that you were referring to removing the negative cable, as opposed to switching it....

If you give me the year, or better still the serial number, of the engine, I'll post up a wiring drawing....

Chris..........

 

[lmannyr]

Re: Dead Batteries? Bad Alternator? Not Charging?

The boat is an '89 but the engine was rebuilt in 2000 with a 2000 block.

I remember back in the day I used to test to see if the alternator on my car worked by removing a cable on the battery. if the engine kept running, the alternator was good, if not the alternator was toast.

I know it's not supposed to be done on boats but isn't removing the cables the same as putting the switch on OFF? Just curious.

Also, the previous owner installed a single bank Guest (Marinco) charger. Problem is there are 2 batteries. What are my options to set this charger up to charge both batteries?

Thanks for you help Chris...

 

[achris]

Re: Dead Batteries? Bad Alternator? Not Charging?

The boat is an '89 but the engine was rebuilt in 2000 with a 2000 block.

Are the electrics and all the other gear from 1989?

I remember back in the day I used to test to see if the alternator on my car worked by removing a cable on the battery. if the engine kept running, the alternator was good, if not the alternator was toast.

CRINGE!!!

I know it's not supposed to be done on boats but isn't removing the cables the same as putting the switch on OFF? Just curious.

Yes... DON'T DO IT!!!

Also, the previous owner installed a single bank Guest (Marinco) charger. Problem is there are 2 batteries. What are my options to set this charger up to charge both batteries?

Thanks for you help Chris...

Not familiar with this GUEST you speak of... I have 2 batteries in my boat... Just a simple OFF-1-2-BOTH switch... Job done!!

Chris......

 

[lmannyr]

Re: Dead Batteries? Bad Alternator? Not Charging?

I don't know if the electronics are new or original. Here is a link to another post with the fire arrestor off, dunno if will help. I can take more pics if you want.

Post #17
http://forums.iboats.com/showthread.php?t=273088

Thanks