1980 Sea Ray Sundancer Battery problem

[John Cooper]

Hi, I hope someone can give me some info, i recently bought a 1980 SeaRay sundancer 26 ft, with two Mercruiser 470 engines. i had electrical work done on the starboard engine, to get it to start, I had to install a alternator and bypass the built in regulator. I read that the starboard engine is the one that controls the house battery. Is there a house battery hidden somewhere in the boat?, I did some electrical checking, and found when i turn the battery selector to "OFF" I still get some voltage at the connection at the solenoid, it drains down fairly quickly, leading me to believe there s a battery somewhere on the boat

 

[Scott Danforth]

Start chasing wires

How is the transom and stringers?

 

[jecooper]

thanks for the reply, i did chase some wires from the solenoid, one went to the circuit breaker, i think one went to the alternator, one went into a wiring harness that i couldn't track. The transom and stringers look good from what i can see, with two 470 engines in the hold, it is extremly tight looking into it. I added a second battery to each engine, just so i would have a back up if needed. It's a mystery to me when i turn off the battery selector, and continue to see voltage on that wire, and see it slowly drop in a short time, eventually it will read zero volts.

 

[Scott Danforth]

you will want to either take moisture readings or to test drills.

80's SeaRays were not the highest build quality

 

[mike_i]

You have something that is charged then slowly discharging when you flip the switch off. It doesn't sound like you have a mystery battery. How long does it take for the voltage to drop to zipo?

"It's a mystery to me when i turn off the battery selector, and continue to see voltage on that wire, and see it slowly drop in a short time, eventually it will read zero volts."

 

[jecooper]

You have something that is charged then slowly discharging when you flip the switch off. It doesn't sound like you have a mystery battery. How long does it take for the voltage to drop to zipo?

"It's a mystery to me when i turn off the battery selector, and continue to see voltage on that wire, and see it slowly drop in a short time, eventually it will read zero volts."

i did some more testing, when i energize the battery switch to on, for a few minutes, then turn it off, i get voltage that slowly drains down to 1 then zero, if i have the cabin lights on, and do this, it drains down to 1 then zero very fast, i'm sure there has to be a battery somewhere, i've searched from bow to transom, and can't find any kind of battery, i'm absolutley frustrated

 

[jecooper]

You have something that is charged then slowly discharging when you flip the switch off. It doesn't sound like you have a mystery battery. How long does it take for the voltage to drop to zipo?

"It's a mystery to me when i turn off the battery selector, and continue to see voltage on that wire, and see it slowly drop in a short time, eventually it will read zero volts."

i have taken the positive leads off all the batterys, just to make sure i'm not getting some kind of feed back, the voltage is still there, it will discharge rapidly if i turn on cabin lights.

 

[jecooper]

You have something that is charged then slowly discharging when you flip the switch off. It doesn't sound like you have a mystery battery. How long does it take for the voltage to drop to zipo?

"It's a mystery to me when i turn off the battery selector, and continue to see voltage on that wire, and see it slowly drop in a short time, eventually it will read zero volts."

i don't know what is on the boat that could possibly hold a charge, except a battery. i just have the standard, GPS, fish finder, Windlass. none of these have internal batterys.

 

[dingbat]

i did some more testing, when i energize the battery switch to on, for a few minutes, then turn it off, i get voltage that slowly drains down to 1 then zero, if i have the cabin lights on, and do this, it drains down to 1 then zero very fast, i'm

Sounds like your reading a capacitor discharge somewhere in the circuit.

Why did you have to disable the voltage regulator?

 

[jecooper]

Sounds like your reading a capacitor discharge somewhere in the circuit.

Why did you have to disable the voltage regulator?

When i bought the boat, the engine would turn over but not fire, i chased wires for five days, took it to a shop, they said the regulator most likely had a bad diode, so went with the alternator conversion, They also replace 3 wires from the engine compartment to the main board, got it running, if i leave the battery connected, it will drain the battery overnight, that is how i found the strange problem i have now, i don't know where any capacitor might be, i've islolated most all my equimpent one at a time, and that phantom voltage persists.

 

[jecooper]

You have something that is charged then slowly discharging when you flip the switch off. It doesn't sound like you have a mystery battery. How long does it take for the voltage to drop to zipo?

"It's a mystery to me when i turn off the battery selector, and continue to see voltage on that wire, and see it slowly drop in a short time, eventually it will read zero volts."

also, if i leave the battery connected overnight, it will drain the battery.

 

[dingbat]

When i bought the boat, the engine would turn over but not fire, i chased wires for five days, took it to a shop, they said the regulator most likely had a bad diode, so went with the alternator conversion, They also replace 3 wires from the engine compartment to the main board, got it running, if i leave the battery connected, it will drain the battery overnight, that is how i found the strange problem i have now, i don't know where any capacitor might be, i've islolated most all my equimpent one at a time, and that phantom voltage persists.

Not sure what to tell you at this point. I could not doubt troubleshoot it in short order in person but the limited amount of info you’ve conveyed so far gives little to go on.

Draining a battery overnight is a large draw down. Shouldn’t be hard to isolate.

Where exactly are you measuring at the switch. Interested in this charging upgrade as well. Don’t know why you won’t just replace the regulator.

Just for giggles, disconnect the power to the bilge pump(s) and starters at the solenoid and see what happens. Both are notorious for motor windings shorting to ground causing dead batteries

 

[jecooper]

Not sure what to tell you at this point. I could not doubt troubleshoot it in short order in person but the limited amount of info you’ve conveyed so far gives little to go on.

Draining a battery overnight is a large draw down. Shouldn’t be hard to isolate.

Where exactly are you measuring at the switch. Interested in this charging upgrade as well. Don’t know why you won’t just replace the regulator.

Just for giggles, disconnect the power to the bilge pump(s) and starters at the solenoid and see what happens. Both are notorious for motor windings shorting to ground causing dead batteries

I switched because it was cheaper, a new regulator costs, about $600, and would still not be sure if the problem might be in the stator, a change out only cost about $200, and i trust a alternator more than the original set up. i have tried to check for amperage at the batterys, but according to my tester it showed no amps, so guess it might be miliamps. Thanks for your input.

 

[jecooper]

I switched because it was cheaper, a new regulator costs, about $600, and would still not be sure if the problem might be in the stator, a change out only cost about $200, and i trust a alternator more than the original set up. i have tried to check for amperage at the batterys, but according to my tester it showed no amps, so guess it might be miliamps. Thanks for your input.

also, i measure the mystery voltage, at the solinoid, and at the distribution panel in the boat, as said earlier, i've disconnected the positive battery connections, unplugged the main connector on the engine, and the voltage is still there. I have all wiring, that i know of going threw the battery selection switch.

 

[jecooper]

you will want to either take moisture readings or to test drills.

80's SeaRays were not the highest build quality

I'm taking your advise and looking for possible problems with transom, when you said do test drills, just where would i do the drilling? with the two 470 engines, there is not much room to access the inside of the transom, would you drill from the outside and patch the holes with resin?

 

[Scott Danforth]

inside the bilge, about 1" above the inside of the bottom of the hull. start by drilling 3-4 inches away from the transom drain plug. drill about 3/4" deep. then move outward about 6" and repeat.

also drill into your stringers, suggest 2-3" up from the hull

if your shavings are light colored, dry and smell like fresh cut wood and fiberglass you are good. just mix up some epoxy to seal the test holes

if your shavings are dark, wet, and smell like rotten leaves. time to pull the drives and motors.

 

[jecooper]

inside the bilge, about 1" above the inside of the bottom of the hull. start by drilling 3-4 inches away from the transom drain plug. drill about 3/4" deep. then move outward about 6" and repeat.

also drill into your stringers, suggest 2-3" up from the hull

if your shavings are light colored, dry and smell like fresh cut wood and fiberglass you are good. just mix up some epoxy to seal the test holes

if your shavings are dark, wet, and smell like rotten leaves. time to pull the drives and motors.

thanks for the advise, but there is no way i have access to the inside bottom area of the transom, without pulling the engines, there is no room either side of either engine to gain access, the only way i can look around down there, is to take my camera and take pictures, or short videos just to see whats down there.