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

[toyotaspeed90]

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 battery
12.(something)v is read at the starting battery

So - 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?

[Grillmeister]

Have fun and enjoy the summer!

[toyotaspeed90]

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]

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]

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]

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]

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]

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]

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]

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]

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?

[toyotaspeed90]

So.... as it turns out....

The 2nd solenoid has nothing to do with charging....

I pulled the starting battery and found the nasty original wiring.... there was 1 cable that connects the starting battery to the isolator along with had 4 other wires tie off of it. The connections were bad and some of the wrapping put over the connections had disintegrated and may have been touching metal. I replaced that cable with a new 8ga cable with good ends on both.... the small wires that also ran to that were then tied to a new fuse and run to the battery connection separately.

All of the connections at the isolator were replaced including another cable from the isolator to the solenoid.

After doing this - the rig wouldn't stay running. There was a relay that someone installed aftermarket above the driver battery that I could hear keep clicking... so I started to investigate.

Turns out there was a factory 4 wire connector that someone tied this relay into (as a switched source)... they then zip tied the connector to where the other wires hang off the end of the firewall.... however there wasn't protection on the wires.... time, heat and vibration against the zip tie caused 3" or so of each wire on the connector to disintegrate, arc to one another, melting the outer sheathing.... amazed it didn't cause more problems. Cut back the harness and fixed all of that.

Turns out the rig wouldn't stay running because I missed one of the (many) connections at the starter solenoid for the battery (guessing it was the power that feeds the fuel pump / oil pressure switch system)... however had it run I wouldn't have found the other problem.

After all of the wires & connections being replaced.... both batteries charge off the alternator.

The 2nd solenoid is connected to a switch inside the vehicle that is labeled as "emergency start"... which feeds power to the starting battery from the deep cell battery when pushed. This wasn't previously working because of some of the bad connections. The reason it seemed this was part of the system is because when the solenoid is activated it then directly connects the deep cell to the starting battery....

With all of that fixed... the flashers still don't work. I haven't been able to identify where the brake switch / hazards are fed their 12V from.

[ksg5000]

toyotaspeed90 wrote:
Actually it isn't the isolator, as I found out later.

The solenoid isn't receiving a switched 12V.... if I supply 12v the solenoid switches on and all terminals on the isolator show a high 13v reading.

I've got some wire chasing to do... I doubt it's something as nice and simple as a blown fuse.... none of the glass fuses in the fuse box are bad... there have been numerous pieces of wiring that have been done horribly, for instance: .....

Had similar problem - too many RV mechanics over the years -- too many wires with some leading nowhere. Relays put in place which didn't make sense etc.

I solved part of my problem by simplifying a few things. I knew the middle prong of the solenoid was supposed to be energized by turning the ignition key -- so I ran a wire from the solenoid through a grommet in the floor board to the radio fuse (piggy back fuse).

[Grillmeister]

I gave up trying to make everything work perfect. The rats nest of wires under the dash is enough to drive you to drink and I don't need any help there.

When I ran a new wire, fuse and relay to my fuel pump I found an ignition on position power wire for my relay and used that. I figured it would be much more reliable than the old factory wires. So far so good.

Have a good trip, hope you get some sun.

[toyotaspeed90]

well.. I don't have it sorted out... I've figured out the "why is this happening"... I haven't figured out "what is causing that to be the problem" part yet.... it was raining pretty heavily and I, well... was done at that point.

Will be back at it when I get home from work today.