Greetings, I'm the new owner of 32-289 (a 2007). I'm having trouble finding the battery isolator to verify my inverter battery charger and battery charger are wired correctly. From Dave at the factory, I got a 2005 Operator's Manual and a 2008 Operator's Manual. Both say the inverter battery charger should be wired to the post on the isolator leading to the house battery bank and the battery charger should be wired to the posts on the isolator leading to the start battery and bow battery bank. But, I can't find anything that looks like an isolator. Above the fresh and washdown pumps I have two solenoids and a combiner but not sure if this setup takes the place of the isolator. Does anyone with a similar vintage 32 have a picture / location of the isolator? I haven't attempted to trace the alternator wiring to try and find the isolator downstream of that, but that's my next step. Thanks in advance, Ryan

Ryan, my 2006 NT32 has the battery isolator wired to the battery charger. I’m enclosing a picture of the setup from the original pictures provided by NT during the boat build. The isolator is the blue finned component, wired to the yellow Xantrex battery charger. It’s a West Marine Model 389791, and no longer available. It’s actually a Charles Industries isolator, model 93-BI160/3-A. Charles bowed out of the marine electronic business in 2016. The factory pic is a little crooked and out of focus, but you can zoom in and see where they mounted the isolator. John Baczek NT32-266, Puffin Watch Hill, RI

Oops, forgot the pic…

On my 2002 NT 32 the battery isolator is in the same position as in the photo. If your isolator is the original diode type isolator you should consider replacing it with a FET isolator. The diode type isolator is not as efficient as the FET type. The diode isolator has a voltage drop of approximately 0.7 volts versus the FET at 0.02 to 0.1 volts. This can make a big difference in the charging current available to charge your batteries. I replaced my original isolator with a Victron Argofet. It’s a quick and inexpensive upgrade. Tony Torphy NT 32-225 Snorri Sent from my iPhone > On Oct 15, 2024, at 10:53 AM, Puffin via Sentoa <sentoa@lists.sentoa.org> wrote: > >  > Oops, forgot the pic… > > > > <IMG_2398.JPG> > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org

I want to second Anthony’s (Tony’s) recommendation. Diode isolators are bad/ old technology.. As well as their inherent voltage drop, they are prone to failure. The voltage drop may not seem like much, but it’s a significant issue when charging from your alternator. As Tony said, there’s a really simple/ easy solution. Replace it with the Victron Argoget FET isolator. And while you’re at it label the wires. Some additional comments: My 2005 NT 32-251 was wired as in the photo. When I started exploring the wiring I found some “interesting” issues: 1. As in the photo my boat had 3 outputs from the Xantrex battery charger going to the 3 battery bank posts on the isolator (1 post for each of the 3 battery banks: Engine, House and Bow Thruster). The prior owner had a boat yard install a Magnum 2000W inverter/charger, possibly to replace an original inverter/ charger. The boat yard appears to have followed the Magnum install instructions and wired the Magnum directly to the House bank. The effective result was that BOTH the original Xantrex charger and the new Magnum inverter/charger were charging the House bank. I removed the charge output from the Xantex to the House bank isolator post. 2. Most surprising in my exploration was to find that the charge wire from the isolator to the Bow Truster bank was on the same isolator post as the House Bank! This was definitely a WTF moment. The effect was those two banks (bow and house) were paralleled! I can only speculate why or when this was done. The story gets even more interesting (bizarre?) when I pulled the 2 Group 24 bow thruster batteries. Markings on them suggested they dated from the original owner and were probably at least 10-15 years old. Needless to say, I replaced them. I rather enjoy electrical projects. My best advice is when in doubt draw a picture. As for sorting out wiring, cable ties are cheep and easy to replace. Don’t be afraid to cut some to help see where a wire goes. ~Tom Patterson NT 32-251 (2005) PACIFIC LOON > On Oct 15, 2024, at 08:19, Anthony Torphy via Sentoa <sentoa@lists.sentoa.org> wrote: > > On my 2002 NT 32 the battery isolator is in the same position as in the photo. If your isolator is the original diode type isolator you should consider replacing it with a FET isolator. The diode type isolator is not as efficient as the FET type. The diode isolator has a voltage drop of approximately 0.7 volts versus the FET at 0.02 to 0.1 volts. This can make a big difference in the charging current available to charge your batteries. I replaced my original isolator with a Victron Argofet. It’s a quick and inexpensive upgrade. > > > Tony Torphy > NT 32-225 > Snorri > > Sent from my iPhone > >>> On Oct 15, 2024, at 10:53 AM, Puffin via Sentoa <sentoa@lists.sentoa.org> wrote: >>> >>  >> Oops, forgot the pic… >> >> >> >> <IMG_2398.JPG> >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org

Hi, Returning the solution to the thread in case someone comes across this in the future. The attached picture is what I have on the forward starboard side engine room bulkhead, I originally thought the center solenoid was just that, a solenoid controlled by the Parallel switch on the dash. It looks the same as the 'Start Solenoid' but, as it turns out, it's an ACR. So, my inverter charges the house bank by being directly connected to it. The 'House Battery' cable in the attached diagram is a red that runs to the house bank positive. Charging voltage coming from the house bank to the center ACR flows to both the Engine Battery and 'Bow Battery Link' ACR as the center ACR is open due to the incoming charge voltage from the house bank. House bank positive has: 1/ DC+ from inverter 2/ positive to DC panel 3/ red running to center ACR on bulkhead. I assume, but will confirm, the engine alternator charges just the Engine Battery. Charge voltage comes over the 'Engine Battery' cable on the 'Start Solenoid'. It then flows to the 'Bow Battery Link' ACR and since the center ACR is open, also the house batteries through the 'House Battery' cable. Thanks to everyone who helped on an off-list. [image: Screenshot 2025-01-06 at 10.26.27 AM.png] -Ryan On Tue, Oct 15, 2024 at 12:42 PM Tom Patterson via Sentoa < sentoa@lists.sentoa.org> wrote: > I want to second Anthony’s (Tony’s) recommendation. Diode isolators are > bad/ old technology.. As well as their inherent voltage drop, they are > prone to failure. The voltage drop may not seem like much, but it’s a > significant issue when charging from your alternator. As Tony said, there’s > a really simple/ easy solution. Replace it with the Victron Argoget FET > isolator. And while you’re at it label the wires. > > Some additional comments: > My 2005 NT 32-251 was wired as in the photo. When I started exploring the > wiring I found some “interesting” issues: > > 1. As in the photo my boat had 3 outputs from the Xantrex battery charger > going to the 3 battery bank posts on the isolator (1 post for each of the 3 > battery banks: Engine, House and Bow Thruster). The prior owner had a boat > yard install a Magnum 2000W inverter/charger, possibly to replace an > original inverter/ charger. *The boat yard appears to have followed the > Magnum install instructions and wired the Magnum directly to the House > bank.* The effective result was that BOTH the original Xantrex charger > and the new Magnum inverter/charger were charging the House bank. I > removed the charge output from the Xantex to the House bank isolator post. > > 2. Most surprising in my exploration was to find that the charge wire from > the isolator to the Bow Truster bank was on the same isolator post as the > House Bank! This was definitely a WTF moment. The effect was those two > banks (bow and house) were paralleled! I can only speculate why or when > this was done. The story gets even more interesting (bizarre?) when I > pulled the 2 Group 24 bow thruster batteries. Markings on them suggested > they dated from the original owner and were probably at least 10-15 years > old. Needless to say, I replaced them. > > I rather enjoy electrical projects. My best advice is when in doubt draw a > picture. As for sorting out wiring, cable ties are cheep and easy to > replace. Don’t be afraid to cut some to help see where a wire goes. > > ~Tom Patterson > NT 32-251 (2005) > PACIFIC LOON > > On Oct 15, 2024, at 08:19, Anthony Torphy via Sentoa < > sentoa@lists.sentoa.org> wrote: > > On my 2002 NT 32 the battery isolator is in the same position as in the > photo. If your isolator is the original diode type isolator you should > consider replacing it with a FET isolator. The diode type isolator is not > as efficient as the FET type. The diode isolator has a voltage drop of > approximately 0.7 volts versus the FET at 0.02 to 0.1 volts. This can make > a big difference in the charging current available to charge your > batteries. I replaced my original isolator with a Victron Argofet. It’s a > quick and inexpensive upgrade. > > > Tony Torphy > NT 32-225 > Snorri > > Sent from my iPhone > > On Oct 15, 2024, at 10:53 AM, Puffin via Sentoa <sentoa@lists.sentoa.org> > wrote: > >  > > Oops, forgot the pic… > > > <IMG_2398.JPG> > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org >