Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 10-16-2015, 03:04 PM   #1
Senior Member
 
kjackson's Avatar
 
Join Date: Jul 2012
Posts: 276
Electrical problem

I'm having an issue with my engine batteries not charging while driving. At face value it appears to be a bad/failing alternator but there's another symptom that's baffling me. Here are some details:

Measuring the voltage of the engine batteries:
Plugged into shore power, engine off: 13.8V
After driving 2 miles, engine running: 12.8V
After driving 5 1/2 hrs, engine running: 12.3V

Here's the puzzling (to me) symptom: The house batteries are full when I unplug but after the 5 1/2 hr trip they are at about 90% charge. That's the same drop as when we dry camp over an entire night.

The drop in engine batteries I'd say its the alternator but why would house batteries drain faster than usual?

Is it possible the battery separator is engaged, draining the house and engine batteries at the same time? I'm talking out of total ignorance on this point...

I'm taking it in for service next week but wanted advice from the forum so I can discuss it intelligently with the tech.

Thanks!
__________________

__________________
Chasing 70 (degrees F) in a 2004 Travel Supreme MH, 2015 Jeep Wrangler, mountain bikes, hiking boots and swim shorts.
kjackson is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 10-16-2015, 03:22 PM   #2
Senior Member - DIYer
 
Waiter21's Avatar


 
Ford Super Duty Owner
Join Date: Nov 2014
Location: NW Ohio
Posts: 3,387
If the engine is running, the idolator solenoid should be energized, so yes, the coach battery and the chassis battery are effectively tied together.

Thats probably why you are able to drive 5 1/2 hours.
__________________

__________________
1999 Fleetwood Southwind 35S (Ford F53 6.8L V10) - Toad 2003 Saturn Vue.
(www.1999Southwind.com)

It won't do MACH 2, but I can get a sandwich and take a pee.
Waiter21 is offline   Reply With Quote
Old 10-16-2015, 03:27 PM   #3
Senior Member
 
dennis45's Avatar


 
Join Date: Jun 2012
Location: BC
Posts: 6,480
What does your voltmeter on the dash say when the engine is running? Should read around 14 volts. If less, the alternator is not charging. This is likely due to a failed alternator.
If the alternator is not charging, the BIRD solenoid will stay switched to the chassis batteries because it cannot see sufficient voltage to switch to the house batteries.
The house batteries are now isolated and subject to whatever draw you have turned on without any charge current from the alternator.
__________________
Dennis & Carol
2003, 4006, 41' DutchStar, Spartan, ISC 8.3L W/BanksPower - 2013 Honda CRV, BlueOx Baseplate, Aventa Bar & Patriot Brake. And the 04 Bird, Sunshine Car.
dennis45 is online now   Reply With Quote
Old 10-16-2015, 06:33 PM   #4
Senior Member
 
wa8yxm's Avatar
 
Damon Owners Club
Workhorse Chassis Owner
Join Date: Mar 2009
Posts: 22,829
There are basically two types of isolator systems.

The older and still most common one when you crank her up the solenoid engages and the batteries are connected.. Sounds like yours is working as designed.

There is one version that measures voltage and connects when it's over a set point, likely in the 13 volt range. But I DO NOT KNOW if that works both ways or only house to chassis.

It is possible to make House to chassis work on voltage but chassis to house on the ignition switch and if that's the case yours is still working as designed.

I'd have the charging system (Engine) tested.

NOTE: on vehicles with old fashion "V" belt fan belts.. I've seen belt tension kill the alternator.. Like 5 different cars including a couple dead in the middle of the road.
__________________
Home is where I park it!
wa8yxm is offline   Reply With Quote
Old 10-16-2015, 07:44 PM   #5
Senior Member
 
kjackson's Avatar
 
Join Date: Jul 2012
Posts: 276
Quote:
Originally Posted by dennis45 View Post
What does your voltmeter on the dash say when the engine is running? Should read around 14 volts. If less, the alternator is not charging. This is likely due to a failed alternator.
If the alternator is not charging, the BIRD solenoid will stay switched to the chassis batteries because it cannot see sufficient voltage to switch to the house batteries.
The house batteries are now isolated and subject to whatever draw you have turned on without any charge current from the alternator.
The gauge is needle is just over the 12 and is confirmed by my voltmeter reading after the 5 1/2 hr drive showing 12.3V.

Might be showing my ignorance here but I don't think I have a BIRD solenoid. I have a Sure Power Industry battery separator. Would they work the same and stay switched?

Thanks for the reply.
__________________
Chasing 70 (degrees F) in a 2004 Travel Supreme MH, 2015 Jeep Wrangler, mountain bikes, hiking boots and swim shorts.
kjackson is offline   Reply With Quote
Old 10-16-2015, 11:23 PM   #6
Senior Member
 
dennis45's Avatar


 
Join Date: Jun 2012
Location: BC
Posts: 6,480
Quote:
Originally Posted by kjackson View Post
The gauge is needle is just over the 12 and is confirmed by my voltmeter reading after the 5 1/2 hr drive showing 12.3V.

Might be showing my ignorance here but I don't think I have a BIRD solenoid. I have a Sure Power Industry battery separator. Would they work the same and stay switched?

Thanks for the reply.

Still betting on the failed alternator. Not familiar with the Sure Power system but from the symptoms you describe, I believe it works the same way and that is why you are seeing the run down on your house batteries.
I think once you replace the alternator and get 14 volt charging, it will take care of both sets of batteries.
__________________
Dennis & Carol
2003, 4006, 41' DutchStar, Spartan, ISC 8.3L W/BanksPower - 2013 Honda CRV, BlueOx Baseplate, Aventa Bar & Patriot Brake. And the 04 Bird, Sunshine Car.
dennis45 is online now   Reply With Quote
Old 10-17-2015, 05:17 AM   #7
Senior Member
 
Join Date: Jul 2014
Posts: 9,911
It looks like some Sure Power Separators are a simple key activated battery combiner.

Others have voltage sensing circuits, like BIRDs and BIMs.

Research the model #

If It is not voltage sensing and your alt. is bad, you will be running down house and chassis batteries, while driving.
__________________
twinboat is online now   Reply With Quote
Old 10-19-2015, 09:01 AM   #8
Senior Member
 
kjackson's Avatar
 
Join Date: Jul 2012
Posts: 276
Quote:
Originally Posted by twinboat View Post
It looks like some Sure Power Separators are a simple key activated battery combiner.

Others have voltage sensing circuits, like BIRDs and BIMs.

Research the model #

If It is not voltage sensing and your alt. is bad, you will be running down house and chassis batteries, while driving.
It's a Sure Power 1315-200. According to a description I found:
Once the engine has started, the Battery Separator monitors the chassis battery and charging system. When the charging system reaches 13.2 Volts, indicating a charged main battery and functioning charging system, the Battery Separator will engage, connecting the auxiliary battery bank to the vehicle charging system. If the drain on the charging system by the auxiliary battery bank reduces the system voltage below 12.8 volts, the Battery Separator will disconnect the auxiliary battery bank, thus protecting the chassis charging system. The process is repeated until the charging system is turned off.

With a bad alternator, the charging system never gets above 13.2V. The battery separator will not engage. Could this point to a bad battery separator also?

Thanks for you help!
__________________
Chasing 70 (degrees F) in a 2004 Travel Supreme MH, 2015 Jeep Wrangler, mountain bikes, hiking boots and swim shorts.
kjackson is offline   Reply With Quote
Old 10-19-2015, 08:28 PM   #9
Senior Member
 
Join Date: Jul 2014
Posts: 9,911
There are 2 things to check.

1 Make sure the "Boost Switch" is momentary and funtioning properly.

2 Make sure that if the "Auxiliary Start" funtion is wired in, it is connected to the start terminal of the key switch and not the run position. If wrong, it will stay engaged, when the key is on, no matter what the volts are.
__________________

__________________
twinboat is online now   Reply With Quote
Reply

Tags
electrical



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
I have electrical problem with my RV hyd9591 Class C Motorhome Discussions 30 08-16-2015 02:35 PM
Electrical problem yp33d Class A Motorhome Discussions 7 07-05-2015 11:29 AM
1996 Terry Electrical Problem HighKountry Travel Trailer Discussion 4 09-22-2014 11:50 AM
2004 Windsor electrical problem Jmyates Monaco Owner's Forum 4 04-18-2014 02:46 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:26 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.