Battery Isolators,Separators, and Switches?

Thank you for your reply.

I confirmed the ACR is grounded and no failed fuses.

When I started the engine, the ACR B post (from the starter battery reads 14 volts but the A post (connected to the house batteries) reads 12.7 volts.

I would expect the A reading to match at 14 volts to indicate the ACR was operating correctly.

Does this confirm a failed ACR?
 
I would confirm that the control wire(red) it not tied to anything , and check the ground connection is clean. If so, the ACR is probably not working. Have you tried the other direction with either solar charge or shore power? Here is the BlueSea ACR trouble shooting guide
 
Where are these wires going? That will answer the switch question since they would be using the proper wires from here.

IMG_9825.jpeg
 
As I have said before, you should look at the control wire (red) this would be the one that is connected to the remote switch . SMB was not big on installing the switch. If the red wire is connected to 12 volts it will combine the batteries. If grounded it will disconnect the batteries. If floating or open it will be in auto mode. Also again check the ground connection.
 
Scalf77,
Just reading your 4/2012 report on the Battery Separator: Sure Power 1315-20
I have a 2003 E350 Sportsmobile and in 04 they (Sportsmobile West) replaced the original battery separator with a model 1315.
Fast forward to 08/2024 and I have an issue with the separator.
Engine running and I have 13+v registering on the house system. Refrigerator operating correctly.
Turn engine off and in 15/30 seconds there is a click in the separator box and the house is without power.
Hook up shore power and it will not restore power to the house system
Is it fair to assume that the Battery Separator is defective? I found your reference to crude very interesting. Could this be the culprit to the house disconnect? The reality is the Sure Power is 19 years old. I see new ones are in the $215 range on ebay.
I have been very satisfied with the existing Sure Power and not really interested in re-inventing the electrical wheel.
Very interested in your recommendation(s)/ solutions.
HIGHCOUNTRYMIKE 2003 FORD E350 SPORTSMOBILE 325,000 4X4 7.3
 
It sounds like your SurePower is connecting, but it sounds like your house battery is dead. When the surepower disconnects, you loose house power. What it the voltage of house battery when engine not running?

If the house battery is two low many shore power chargers won't start charge.

Do you have solar?
 
This just started yesterday on a fast trip to Southern Utah.
This is a new battery and has worked fine for several weeks.
I am unable to read the house voltage because when it (Separator) clicks off there is zero power to a plug. I have the shore power hooked up to night but as I mentioned there is now power to the house system. When I start the engine, the Separator clicks, and the system is powered up. Frig comes on, I can use lights etc.
 
Again,

The separator appears to be working, upon starting engine alternator fires up, voltage on Start Battery side of the Separator goes above 13.2 volts and the separator connects the house and start batteries. At this time you appear to have power on the house side of things and all is working well.

Now, when you turn the engine off, the voltage starts to decay and drops below 12.8 (that is your time delay between before you hear the click). Now the two battery systems are disconnected or separated from each other.

The Separator is not between your house battery and shore power charger.

You should be able to read the voltage on house battery in this mode.

So I would start checking stuff on the house battery side.
 
I ended up replacing my Blue Sea 7620 which solved the problem. The click mine makes about 30 seconds after starting the engine connects the electrical circuit so my alternator charges the house batteries. That wasn’t happening with the replaced isolator. As I understand, the isolator will not click to connect the circuit if the starter battery is low (under 12 volts I believe) to make sure the starter battery comes up to full charge before charging the house batteries.
 
Mike: You need to be able to get your voltmeter on the house battery when the van is not running....that will tell us a lot.


Your shore power issue may be a circuit breaker/fuse issue but we need more details on what "no power to the house system" means. ...no 12V power ...no 120VAC power?
 
Last edited:
TO: Scalf77, 2JT and boywonder,
I was dreading trying to get a voltage reading on the house battery. Keeping in mind it is a new battery. The last thing I wanted to see was a zero or Lo on the voltage meter.
Turned out I did not need a voltage meter to determine the voltage. As I was checking the battery cable the negative cable came freely to me. It was not connected to the battery. (I did some bumpy roads last week in Utah.) I lowered the battery cleaned the terminals reconnected the negative cable and tightened the positive. I did check the voltage which registered Lo on my meter. Yes, the house battery was "dead" as you all had mentioned. Reinstalled the battery. Took the van on a 45 minute recharging ride up I-5.
Checked the voltage and it is back to normal. I have power in my living quarters.
I would like to thank you guys...you were right it was a battery issue. I'm no longer going to worry about my separator.
HIGHCOUNTRYMIKE 2003 E350 SPORTSMOBILE 4X4 7.3 325,000M
 
So 19 years on a Surepower is pretty good.

I suspect that you have the start assist still hooked up.

Don't have solar

Don't always plug in.

I say this because the crude problem I spoke is enhanced when you don't have a lot of current going across the contacts when they close. The Large solenoid is designed for large current.

The start assist somewhat mitigates this by combining the contacts when you are cranking the engine thus more current.

Solar can just the opposite, it can bring the house up to high enough voltage but not really pushing a lot of current across the contacts.

If you plug in all the time, chances are when you start the van, the house is already full thus not a lot of current going thru the contacts.

If you find the need you can just source the solenoid from Trombetta.

Glad your up and running
 
Hello Greg and all,
I upgraded the old SMB system with Redarc Manager30. The guy that installed the system left the old Sure Power switch in place for fear of making things weird. I had the van parked for 2 weeks and the starting batteries were dead-- it's the 7.3 with the two starting batteries (Odyssey Extreme).
Could the switch be stuck open and slowly drain the battery? Would it be a good idea to get that thing out of there anyway?

Any thoughts would be appreciated.
Thanks
 
Actually I don't see how the Redarc worked being behind the surepower unit. Maybe if it was 1314. The Surepower was also wired wrong from sportsmobile sometimes , that might of made it work also. In any event I would take it out, it could have been a drain on the starter although not a huge one.

You could replace with a Blue Sea Power Post - 5/16"-18 Stud and connect the two cables together.
 
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