1985 Pace Arrow G31 Battery isolator

[Seth Caron]

My 85 Pace arrow will not take power from the batteries. It used to until I overflowed the water tank and because of piss poor design the electronics bay. I replaced the converter, and checked the sentinel and circuit breakers. All are good. 

After prodding around on Google, I found out that it could be the battery isolator. I purchased a very nice isolator designed for a boat. It only has two posts, the old one has three. The wiring diagram it comes with basically says just throw wires on it because polarity doesn't matter. The wiring colors are 2 red, one black. I wired the two reds to the post and the black to the ground. I also replaced a bad fuse in the engine compartment. The batteries take a charge from the plug in, but not the alternator. And when I pull the plug the lights and appliances go dead.

Am I wiring the isolator wrong? I should note that when I removed the black wire from the old isolator after I'd removed both red there was a lot of arcing and sparking. I'm no electrician, but I don't think ground wires alone spark. Is the black some kind of power bearing line? Should I wire it to the posts with the two others? Should I sell the RV and buy a tent?

Thanks in advance

[Rich Thomas]

I would say a combination of both and probably the relay isn't going to work for your application with out modification. just speculation on my part. Can you post a pic of the relay. the new one probably has a insulated ground for fiberglass boats. Try looking at  pplmotorhomes.com type in battery isolation switch. they have a bunch of choices even the old tried and true tin can three post.  Good luck!

[Terry H]

And further, whenever working with 12/24 volts, ALWAYS remove the ground/black FIRST.

When reconnecting, positive/red FIRST.

Any sparking or arcing in the vicinity of a flooded battery is a strong invitation for explosion and fire.

Check the manual for your new isolator. If it has an internal fuse (likely) chances are you blew it. If so it 'may' be replaceable.

[Seth Caron]

[Seth Caron]

[Seth Caron]

The first pic is the new isolator. The second is the old one with a diagram showing how it was set up 

[Rich Thomas]

Sorry I'm not familiar with either of those Seth, maybe some of the other members that are into boating may be able to help out with the new one. The old one is solid state judging from those heat sinks so, it stands to reason you could replace it with a newer solid state one. maybe just not the one you bought.

[Gary Rowe]

Hey Seth I have a 1985 Travelcraft class A  2 cabin and 1 crank battery this is what will work Cole Hersee 48120 Battery Isolator, 140A, Three 5/16" Stud Terminals about $65 hope this helps. Has worked on mine for over a year now. Good luck God Bless Gary