So this is a relatively new vehicle to me. The wiring is somewhat nightmare'ish... both from the factory and from what others have done.1984 E350 Fleetwood Jamboree.2 batteries, an isolator, and 2 solenoids.Battery on the passenger side appears to be mainly a starting battery for the engine. This is a standard battery for starting. It runs directly off to the starter solenoid and has 2 other wiring connectors on that same post as well (guessing mostly for the chasis needs).Battery on the drivers side, just replaced, seems to be mainly for the 'house' and the generator. This is a deep cycle battery.The alternator feeds directly into the isolator.The isolator is a 3 post. 1 wire feeds to a solenoid on the passenger side. The other feeds into a harness, with a quick look can't tell where too.The solenoid on the passenger side, on the same post of the solenoid that the isolator is connected to, feeds off to the drivers side battery post.The generator is wired directly to the deep cycle battery (driver side)When the engine is running, generator off:14.4V is read at the center post of the isolator and at the starting battery.12.28v is read at the other post of the isolator and at the deep cycle battery.Generator running, engine is of:13.8v is read at the deep cycle battery12.(something)v is read at the starting batterySo - in looking online this isn't that atypical of a set up (solenoid and isolator)... I've read that there should be 14.4 on both sides when the engine is running.... but have also read that the purpose of the isolator is to keep the deep cycle separate from the starting battery in the event the deep cycle has voltage spikes and/or running it too low - so you can still start the engine.So, as the title says.... is my isolator doing exactly what it should be doing or exactly what it shouldn't be doing?

Ran out into the rain to go check...The other side of the solenoid in which the isolator is connected to... only feeds to the starter battery.The only thing I can think of... is that that 3rd post of the isolator actually feeds to the deep cycle battery and that the isolator is toast...

ran out again....pulled the wires from the deep cell (except the generator cable as I just changed that to a post connector and it's extremely tight)...also pulled the wire from the isolator that runs into the harness...continuity runs from the isolator wire to 2 similar sized wires that run to the deep cell, but not to the main 4ga cable that runs off the deep cell.With that wire pulled from the isolator there is no discernible voltage across the isolator. Once I reconnected that cable to the isolator (keeping the other 3 larger wires off the deep cell, but the generator cable still connected) there was voltage across all 3 posts of the isolator.

From your voltage readings, IMO your isolator isn't pulling in when you start the engine. If it were, the voltage on both large terminals would be the same.I would expect the generator to only charge the house battery.I have replaced the battery isolator twice on our Minnie. Disconnect the ground wires from both the chassis and house batteries before replacing the isolator as a safety precaution.

Hard to tell on a 84 Class C chassis but typically that kind of setup will do the following:Engine on: Alternator, starting battery, and house battery at same voltage, your 14.4 sounds right for an alternator sourceEngine Off and using generator/shore power: House battery at converter voltage (13.8 in your case) and engine battery resting (call it 12.6). Typically the converter does not charge the engine battery. You might have a boost switch to help the starting battery by manually connecting your house and starting battery together if the starting battery is low.Sounds like your isolator has failed is not working (i.e not connecting house to alternator when voltage > than house battery voltage)Also getting a reading of 12.28 on the house battery at rest is very low (approaching 50%). You need to fully charge that as soon as possible. With a converter operating at 13.8 that couuld take a couple contineous full days. You need to plug in for a while.

Interesting to hear... the deep cycle is brand new (purchased and installed yesterday, was load tested at the battery shop yesterday and passed with flying colors). I'll go plug the system into the house.I've figured out the problem... haven't figured out why it's happening but that it is.The 12v switched signal for the solenoid isn't reading voltage when the key is set to on... when running if I jumper the solenoid switch to 12v then I get a high 13v reading (it's cold and this motorhome isn't cold blooded.... a similar issue as I don't think the electric choke is getting a 12v switched signal either) for both batteries....There's an obvious non original relay under the hood... 3 of the 4 connections are mediocre at best (read, ugly wiring harness & someone who knows enough to get in trouble and not much else)... There's continuity between the relay switched 12v and the solenoid switched 12v.... so will do some wire chasing tomorrow to try and find the problem.Worst case scenario I can find a working 12V switched and run a new relay for the weekend.I appreciate the help & responses.

Battery Isolator - doing exactly what it should shouldn't?

Grillmeister
Explorer
May 30, 2013
Have fun and enjoy the summer!
toyotaspeed90
Explorer
May 30, 2013
Well for now the rig is back home... this is all stuff I plan to look into and taking the suggestions seriously... sounds like a new converter might be the best bet.

Right now.... the focus is on the FJ40 (1970 / partially 1976 Toyota Landcruiser)
Grillmeister
Explorer
May 30, 2013
ksg5000 wrote:

Consider upgrading your converter. I purchased a PD9245 for about $100 - the PD was silent, more powerful (45 amps vs 3), and doesn't deplete water of batteries like the old Magnateks. Easy DIY install with lots of videos/how to's online.

Excellent suggestion, I have installed couple of these and they work great. Best price was E-Bay.

I set up a cheap trick on my rig for connecting the batteries together when ever I am plugged into shore power and want to charge the engine starting battery too. I placed a heavy gauge in line fuse holder to both sides of the booster selenoid, when I want both batteries connected I just put a 30 amp spade fuse in it. This also works if your alternator fails, you can run the generator and with your new powerful converter you can power the engine ignition system to get home (don't ask me how I know this) :B

This should also be a good temperary fix for your current charging problem you are having with the house deep cycle battery, while driving or parked. Just make sure to pull the fuse while camping so you don't kill both batteries. Another reason I take the jump box along.
ksg5000
Explorer
May 30, 2013
I don't dry camp very much anymore and found out quickly that one type 24 battery is insufficient - I added a second in the rear storage compartment. If you add a second battery remember that it needs to be vented to the outside. If your serious about dry camping then upgrading to larger batteries is a big help - space maybe an issue.

Consider upgrading your converter. I purchased a PD9245 for about $100 - the PD was silent, more powerful (45 amps vs 3), and doesn't deplete water of batteries like the old Magnateks. Easy DIY install with lots of videos/how to's online.
YC_1
Nomad
May 29, 2013
As suggested if you have the original charger it may be 3 amps. It took me some time to discover that on my 89. I used a portable charger at the time but changing the existing one out to a smarter one that charges better would be a good investment. I installed a sealed battery under the sink as a secondary.
Grillmeister
Explorer
May 29, 2013
If you have the original converter it only charges at 3 amps. You could run the genny all week and still not top off the battery.

No you don't have room for a bigger battery, I have switched all the lights to LED's to help some. BUT, the refrigerator eyebrow electronics on my 10 year old fridge uses 1/2 amp per hour.

With just the fridge on you are using 1/4 of your usable battery capacity per day. The best I am able to do is 48 hours then I charge a couple hours with the generator to get to about 90%. I have a new three stage 45 amp smart converter/charger.

Another big drain on the battery is the Propane Auto Shut Off Solenoid. If you still have one it is located right next to the LP tank after the rubber hose and before the metal pipes and the wires are connected to the LP detector near the floor somewhere, mine is below the refrigerator. The LP will not flow unless the LP detector is on and reset. Then this solenoid draws power all the time. If the LP detector alarm goes off it close's that valve and no LP will flow until it is reset.

Also if you have the original LP detector it probably is not working, they are only good for about 5-7 years. I tested my original with a lighter on with the flame out and it did not ever go off. My new one goes off in one second. Some people remove that solenoid and by pass it to avoid the power draw.

Some new rigs still use that safety device but I have never seen another one.

BTW Trojan makes a 100 amp hour group 24 deep cycle 12 volt battery. Most of the others are just 80 amps.

I carry a jump box to watch TV with a small inverter to extend my battery time.
Glad all went well with the running gear!
toyotaspeed90
Explorer
May 29, 2013
ksg5000 wrote:
When you say your battery reads "Good" what meter are you using. The battery meter that came with your rig is practically worthless and if your using that as a basis for your concern then stop.

Further - unless your converter has been changed/upgraded you likely have an old Magnatek which are lousy - slow to charge batteries. Also - what type of battery did you install - your rig probably came with a type 24 battery which is pretty small and good for about 3 or 4 days of dry camping.

Not sure - but it's possible that things are working as designed.

I am using the in-'home' meter that registers whether the battery is good.... I was under the assumption it put a load on the battery to determine status... now I'm guessing it's based on voltage (which on a deep cell may not change much until nearly drained). I was in the middle of the woods and only had minimal tools... no battery tester on hand.

Yes, I replaced it with another 24M as there isn't a lot of room.

guessing, yes, the convertor is original.

4-5 days of 'dry' camping is what I'm guessing we did... with that said 28 hours is a LOT less time than 4-5 days.....

and of course this means chasing down the specific issue(s) with this motorhome. May end up adding a 2nd or 3rd battery in the kitchennete to allow for sustained useage.
ksg5000
Explorer
May 29, 2013
When you say your battery reads "Good" what meter are you using. The battery meter that came with your rig is practically worthless and if your using that as a basis for your concern then stop.

Further - unless your converter has been changed/upgraded you likely have an old Magnatek which are lousy - slow to charge batteries. Also - what type of battery did you install - your rig probably came with a type 24 battery which is pretty small and good for about 3 or 4 days of dry camping.

Not sure - but it's possible that things are working as designed.
YC_1
Nomad
May 28, 2013
Running the generator one hour may not fully charge the battery.

Re-read all the previous posts for troubleshooting. Time to grab the voltmeter again. You previously stated all batteries were charging. Could be a blown fuse not allowing one of the relays to engage.
toyotaspeed90
Explorer
May 28, 2013
So - I'm a little frustrated with the motorhome at the time being (just in terms of battery power). ((As a side note I'm extremely pleased with the reliability it gave us.... sitting in long traffic due to the bridge collapse, driving freely down the highway, driving up and down a mountain pass all while towing a somewhat heavy 4x4 vehicle)).

Brand new deep cell installed last Wednesday - it was tested as being in great shape, vehicle was plugged in all night Thursday. Filled the LPG tank around noon on Friday.

By Saturday night the battery was low. We weren't running the furnace and lights were only on sporatically and never for any long duration.

Ran the generator (was able to get it started by using the emergency start button for the reverse intention... IE started the vehicle, hit the switch and had someone start the generator) for about an hour - the battery upon shutting off showed as "Good".

Sunday I got back from wheeling at about 7pm and was told mid-day the battery died and they couldn't start the generator.

Again I got the generator going, ran it for about an hour and all was well.

Driving home yesterday, Monday, and the house battery died again while going down the road.

The only power we were taking was charging 1 phone and the fridge - which I'm assuming when running on LPG that the only electrics running in the fridge is the ignitor and the thermostats.

Thoughts?

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