Isolator replacement?

[QT1]

Still working off items previous owner did not reveal in the sale but was noted on the survey of my new to me 90 350 Sundancer: What would cause these ends to burn on the isolator as indicated in the photo?

 

[Wylie_Tunes]

Loose or poor connections is the most common cause. This may result in both sides of the connection needing replacement. In this case, the cable (or just end) and diode isolator. Losing the isolator in favor of an ACR/VSR may not be a bad thing anyway.

 

[QT1]

During the survey it was noted the burnt plug receptacle for the A/C on the port side. The owner said his connection to shore was loose and contributes the burning to arching

 

[QT1]

Wylie, I'm very interested in your suggestions for either ACR or VSR verses the original isolator. Being I have 3 batteries, what would be the ideal setup for this? Thanks.

 

[Wylie_Tunes]

@QT1

The first drawback to a diode type isolator, is the inherent .7 volt drop between the alternator supply charge and outputs to the batteries.

The next is that in most typical diode isolator systems, we find most of the electrical loads are wired directly to a battery. This tends to leave some possible parasitic draw on the batteries, whenever the boat is not in use.

An ACR/VSR will automatically combine and isolate with banks, without the voltage drop. A better switch setup can allow for all the loads to pass through the switch, meaning nothing is wired battery direct. The exception is a couple things like an auto bilge or active galvanic system.

 

[QT1]

What parts would I need to accomplish this?

 

[Wylie_Tunes]

Twin engines, correct? 3 batteries total? cant tell if youve got 2 banks or 3 banks. The old diode looks like a 3 output, so leads me to believe its a 3 bank boat.

 

[QT1]

Twin 454's, 3 batteries total. I believe it's a 3 bank boat

 

[ttmott]

What parts would I need to accomplish this?

two of these for three battery banks or three to loop the three battery banks
https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A

 

[QT1]

Is there a schematic somewhere to reference installation? I do plan on converting after reading articles related to this better setup and I want to do the conversion myself, safely.

 

[ttmott]

https://www.bluesea.com/resources/170/Battery_Management_Wiring_Schematics_for_Typical_Applications

 

[Wylie_Tunes]

As much as I like the blue seas 7610, I think a single proisocharge 23127 2 x 4 might be the way to go. Id also look to replace at least one of those on/off switches with a 1/2/BOTH and do away with what looks to be a combining solenoid between those two switches.

 

[QT1]

I'm going to try the Blue Seas and see if it fit my needs. I'm taking you recommendation on combining the 2 switches into one. Thanks fellas. Happy New Years

 

[Wylie_Tunes]

Just to clarify/expand on my post above. You would not want to try and run a twin engine, 3 battery, 3 bank setup combined on a single main switch. You will want/need to 2 switch setup. However, with 3 batteries and 3 banks, I would like to replace one of those simple on/off switches with a dual bank switch.

This would allow you to choose which battery is the main cranking and which is the house, as well as allow you to use that house as an emergency cranking battery. Of course, you would still want a means of using either engine cranking battery to start the other engine if needed, which I believe thats what that solenoid is there for.

 

[QT1]

Thanks Wylie for the additional information, very helpful. Now I have to determine which is house and which is starting.