I just installed a new pair of 6V batteries and rewired everything pretty much the same way, except for wiring them in series. Everything's working great except for the isolator that is supposed to give me a charge from the alternator. It's not giving me any juice when the engine is turned on anymore. The generator is providing charge just fine, although it's on the cabin side of the isolator.Here's a quick diagram of my basic wiring:Do I have everything wired correctly? If so, maybe my isolator has gone bad. I did accidentally touch it with a wire when I was removing the old batteries and it gave off a few sparks.

Isolators come in different flavors. What does yours look like?

Hi pNuker,If it is a relay that is energized when the key is on have someone else turn on the key while you listen for a "clunk". If you hear the clunk then check for power on both "sides" of the relay. If there is no clunk check to see that the small wire has power when the key is on. Mine had a fuse before the relay that I've caused to be replaced by auto reset circuit breakers.Relay type isolators do fail and contacts do burn. My Ford OEM one lasted less than a year, in spite of it being rated for 100 amps. The contacts were in poor shape. The "intelligent" design folks put the relay down below the starter battery so the battery has to be removed to service or check the relay. Of course you can't check it with no starter battery. The one I used to replace it is a lot better made. I would not put my inverter through a shunt. Too much chance of a surge taking out the shunt and leaving me without cabin power. I would have a heavy duty manual switch on the inverter as well.

Hey there Mex, here's a pic of it. It's a Camdec 97226-wr.

Is the chassis battery being charged from the alternator? If so check the wiring against the pictures that you hopefully took before the new batteries. The n check the two small control terminals (if it's a solenoid) on the isolator. Once you got the sparks then the isolator or something else could have been zapped. BTW There are several good reasons to disconnect the negative battery cable first and connect it back last. Prevents those sparks is one reason.

Pianotuna's diagnostic procedure is right on the money...I h-a-t-e those solenoid type isolators. I much prefer the Essex type bi-directional "smart" solenoid. They can rate the can solenoid for a billion amps but they'll only carry 60. I even tried the 11880 solenoid with silver contacts years ago and they too were junk.Someone else will chip in about the smart solenoids. Again I love the new stuff. They protect themselves and do not need an ignition signal wire to work.

Battery Isolator Not Working | Good Sam Community

YC_1
Nomad
Dec 02, 2012
pNuker wrote:
Hey GoldenHVAC, there appears to be a voltage drop of about .15 from input to output of the isolator while the engine is running.

To get back on track and answer your question. If there is a high charging situation that voltage might be ok. If the batteries are very close to being full then that voltage is suspect to me. The solenoid is a simple on/off switch. If the switch is closed it should be a dead short and no voltage difference on either side.
YC_1
Nomad
Dec 02, 2012
MEXICOWANDERER wrote:
YC1, I suppose if a manufacturer switched to a thermally conductive potting it would help a lot. But for years it was "over the left shoulder and into the dumpster for burned contact failure" and "Over the right shoulder for burned out coil failures".

I got so tired of addressing this I pushed for using a remote rectifier. End of problems forever. No bird circuits, no contacts, no voltage drop, happier campers.

I agree there is a degree of failure but it is a simple and inexpensive item to diagnose and repair.
YC_1
Nomad
Dec 02, 2012
"My new to me Vision, did not charge the house batteries from the nator."

That is a great workaround. On my last mh before I added the Trik-l-start charger I installed a standard automotive tail light bulb in line between the tow battery systems. It was used only when sitting. A simple alligator clip on each end. This kept charging current very low and when there was enough current it would glow. Once it quit glowing for many hours it was charged. Crude but fun and effective.

Many rv's are not set up to charge the engine batteries when on shorline. I believe Winnebago is now installing the trik-l-start as standard equipment. With the addition of a moderate sized solar panel my batteries were always up.

This said, you probably have a blown fuse that drives the solenoid. It would bug me to not find the cause.
westend
Explorer
Dec 02, 2012
White-Rogers continuous duty solenoid Datasheet.
MrWizard
Moderator
Dec 02, 2012
check out this relay 15-133** SAS-4202 Your Cost $54.50

on this page http://www.texasindustrialelectric.com/relays.asp

this is the kind of thing i prefer when doing a repair/replace project or designing a new project
Cloud_Dancer
Explorer II
Dec 02, 2012
My system was installed at the time of manufacture, and I picked up my motorome at the factory 9 years ago.
The chassis battery consists of two large 12 volt batteries, and the house battery is four 6 volt golf cart batteries.
The alternator is a 160 amp Prestolite Leece Neville.

The Isolator is:
Bi-Directional Isolator Relay Delay Diesel 00-00366-00.

It triggers a solenoid:
White-Rogers/RBM
St Louis MO
Type 586-105111-3 Coil 12 VDC Cont.
Customer # 586-902

It has been working perfectly all these years. The ONLY problem I've ever had with the entire electrical system is recently, the alternator failed to charge after the motorhome was parked for 2 months while I did major repair/mod work on the roof. The problem was one failed slip-ring brush, which now I believe might've been caused by ME.

I only post this because if this solenoid (which is mounted sideways) were to fail, I would replace it with the same one.
tenbear
Explorer
Dec 02, 2012
pNuker, mine failed early on and I replaced it. Originally it was installed upside down. I installed the new one right side up. I notice yours is installed upside down too.

I don't know if this contributes to its short life, but my new one has been going for 7 years or so while the upside down one lasted only about a year.
RoyB
Explorer II
Dec 02, 2012
Mex - I'm covered pretty good with my off-road trailer setup in that respect. I keep charged up using the PD9260C or shore power cable plugged into pedestal or my 2KW generator.

My new problem is adding the second battery bank to the back of the truck so that I can use those batteries to support my hungry two radio toys when I am just out in the truck without the POPUP trailer. I wanted to be able to charge the truck bed added batteries from the alternator when needed. When I connect the two Truck bed batteries to the trailer tongue mounted batteries then I switch the truck auxiliary batteries to be charged from the trailer on-board converter/charger.

I think I will be ok with what I am thinking about doing. Won't really know for sure until I am out in the woods depending on it. That's when everything goes dark at 10PM and the wild javelina pigs start closing in for the kill hehe...
MEXICOWANDERER
Explorer
Dec 02, 2012
RoyB, I for one, agree. If two-way charging is not part of the program to me it would make little sense to abandon the excellent quality Blue Sea product. But I keep seeing those posts wherein "My chassis battery goes flat even though I am plugged in".
RJsfishin
Explorer
Dec 02, 2012
My new to me Vision, did not charge the house batteries from the nator.
And w/o a wiring diagram to find why the solenoid wasn't being energized, I just connected a # 8 wire from each side of the solenoid (thru a 40a CB) to a 40 amp toggle switch on the dash. Except for remembering to turn it off when I camp, I never had anything work so good. If it dumps the CB now and then, fine.
At least I now know whats going on, and why.