Does alternator charge coach battery while driving?

[Mister Blu]

Fixing to head out on first lengthy trip.  

How am i to know if my coach battery is charged by alternator while driving?  

If it does, is that to say that it will also run fridge on 12V setting while driving? 

Is there some device or hardware that i can put an eye on to confirm?

 

[WME]

IF everything is working as designed your engine will charge the house battery and run a 12v refer when your driving' One thing the 12v will maintain the temp in the refer but is not powerful enough to cool thing  off.

The device that makes this is the isolator, there 2 styles. The solid state one is a rectangular metal box with a finned top. The other is a solenoid type it looks like a small cylinder.

Both will have a large dia cable from the alternator also large cables to the truck battery and house battery

Edited September 25, 2017 by WME

[Mister Blu]

Thank you WME, for the prompt reply.

Where might i find this 'isolator'?  

1986 Sunrader, 210-RD

Anyone having any pictures of isolator.

[WME]

Normally its under the hood mounted near the back of the driver side inner fender.

solid state

Solenoid

 

Edited September 25, 2017 by WME

[linda s]

Sunrader isolates look like the second round ones. Tekonsha makes them. Might have spelled that wrong. 

Linda S

On the firewall drivers side

[Derek up North]

Tekonsha 3-pole N7000.pdf

Tekonsha 4-pole N7001.pdf

Sunrader Wiring Diagram.pdf

[linda s]

Both my Sunraders came with 4 pole which has a separate ground wire.

Linda S

[DanAatTheCape]

you can tell if it is working 2 ways:  use a multimeter   -or- turn on coach 12v dc lights, start engine and watch lights - they should get noticeably brighter

[Bob C]

I installed an LED volt meter under the dash that gives me the voltage that is going to the rear (coach) battery.  This volt showed me that my 3 month old isolator failed on the first day of my 2 week trip.  I would have not known about the failure until my coach battery was dead at the end of the day.  

[hunkaman]

bob c     what brand, model of under dash volt meter did you purchase?  this appeals to me as something I may do. thanks in advance for your help. joe from dover

[WME]

Don't just install a v meter, install something thats useful in these days.  http://www.ebay.com/itm/3-in-1-Dual-USB-Car-Charger-Adapter-Voltmeter-12V-24V-Outlet-Socket-Plug-MA720-/311832361043?hash=item489aa83853:g:4-8AAOSwcaFZELQ-

Too complicated??? try this http://www.ebay.com/itm/Dual-Ports-3-1A-USB-Car-Cigarette-Charger-Lighter-12V-24V-Digital-LED-Voltmeter/391738751186?rt=nc&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D41375%26meid%3D93ac497866e54c3db1d3cd1f38d57b62%26pid%3D100005%26rk%3D5%26rkt%3D6%26mehot%3Dag%26sd%3D272513065199&_trksid=p2047675.c100005.m1851

Edited October 3, 2017 by WME

[hunkaman]

wme - question - I looked at the products you provided links to. thanks. the question I have is this.... does the plug in volt meter (plug in to the cigarette lighter socket) display tell you how the coach battery is charging ? or the motor compartment battery ? ...or both ? I also liked the other product that allows for charging other devices. so same questions for that product as well. thanks in advance for your help. joe from dover

[WME]

I installed several 12v cigarette lighter all around my Toyota, in pre USB days. The plug in would have told me the status of my house batteries. If you just plug it into your dash lighter plug it will tell you your truck battery status and the charging system status. So add an 12v cigg outlet in your RV house to use the plug in on your house battery.

The fancy one just wire into a 12v line in the house and it will keep track of the battery and charging systems, both the alternator and converter. I taped in to a 12v hot going to a light fixture and just mounted one under my cabinet. The charging cords all reach far enough to rest the device on the counter top when charging.

Edited October 4, 2017 by WME

[hunkaman]

wme       thanks,  think I will add this to my rig. joe from dover.

[RaderDog]

I know this is old but here goes…

 

Been searching since September but finally found my Sunrader in Palm Springs. Very excited! I will start on a full Renovation when I get home to Seattle. I’m still in California using the warm weather to do a complete inspection on the vehicle. I ran into my first hiccup. Sunrader house battery charges while hooked up to house power. It is not charging by the alternator while driving. I read through all your posts (very helpful). Unfortunately cannot get the Tekonsha Battery Cut Off Switch - 7001 for a week. I have posted a photo of mine which I would switch out immediately if I could d get it. I am not getting any voltage at any connector + Ground. I am thinking I have a wiring issue. I thought I would run a hot lead from the battery to the switch but not sure if that is or a good idea. Since I’m on the road I don’t want to pull any wiring apart. I appreciate your help in advance. Thoughts? Thanks, Bill

[extech]

1 of the wires on the solenoid should be always connected to the battery in the engine bay. at the bottom of the pic is a circuit breaker that looks questionable. also check at the battery as battery replacement could have left that wire off

[RaderDog]

I should be getting 12 v in somewhere with the engine running correct? Any clue of what part the circuit breaker is? I am getting no change in voltage with the engine running at the house battery.

[DanAatTheCape]

On 9/24/2017 at 9:16 PM, Mister Blu said:

Fixing to head out on first lengthy trip.  

How am i to know if my coach battery is charged by alternator while driving?  

If it does, is that to say that it will also run fridge on 12V setting while driving? 

Is there some device or hardware that i can put an eye on to confirm?

 

I think the thread gives lots of hints on how the system is supposed to work. To answer your question, take your multimeter and measure DC voltage AT THE HOUSE BATTERY.  Then start the engine and measure again.   A fully charged battery that has not been attached to any charging source for awhile should show 12.5VDC. With the engine running, you should see 13-14vdc. 

 

Worth noting that every electrical connection between engine alternator and house battery causes a slight drop in voltage at the battery.  Trying to run a fridge on DC voltage is quite a stretch (IMO).  Possible, but problematic.   Try measuring DC voltade within the frig while in DC mode, as close to the heating element as you can get. When I had a Toy, my frig was completely mechanical. I ran it all the time on gas even when underway.  The only problem I had was twice while in very high winds (40mph) blowing into the unit, it blew out the flame.    I have a casita now which is 12v capable - the threads on 12v mode there are pretty unanimous that DC mode is bad juju. If the wiring - from tow vehicle to house battery to frig are all in great shape it can work, otherwise, not so much.