Community Forums

R F S · 07-23-2013, 07:07 AM

As I get to know our new DP I now find that the house battery is not charging with the coach running. Is there any connection with the energy management system and this circuit? Engine batts. charge @ 13.8vdc and EMS shows coach to charge with shore or genset. I have 2 large solenoids in battery compartment , thinking one is to connect the 2 systems when chassis voltage is low. Other for house to altenator??? 2005 Four Winds Mandalay 40B C-7
R F S

YC1 · 07-23-2013, 07:57 AM

Measure the voltage on the large terminals of the solenoids with the engine running, shoreline disconnected and generator off. If you find the voltage is less on one of the large terminals then measure the voltage on the little terminals. One should be zero/ground and the other should be 13.5 approx. If you find this situation the solenoid is being told to close but it is not doing so. These solenoids can be a common failure item.

No if you don't find voltage on the little terminals the solenoid is NOT being told to close. This could be a simple blown fuse. One control of some of these is the aux start button. Might be emergency start etc. Try your test with the switch being held on. If you then get the solenoid to work you know the wiring and part of the circuit functions.

If you get this far, do a search for BIRD/IRD and you will have a couple of hours of reading.

R F S · 07-23-2013, 09:33 AM

OK Doesn't the "aux start" sw connect both chassis and house together for em. engine starting? Should control voltage at solenoid be present from altenator anytime engine is running? Does one solenoid control charge to chassis and the other to house from altenator thus they should have same readings when engine is running?

GaryKD · 07-23-2013, 12:37 PM

Hi R F S,
Maybe the coach doesn't charge the coach batteries from the alternator. Many coaches do not do this. Consider calling the manufacturer and determining if the coach is wired to do this.

ga traveler · 07-23-2013, 12:48 PM

Quote:

Originally Posted by GaryKD

Hi R F S,
Maybe the coach doesn't charge the coach batteries from the alternator. Many coaches do not do this. Consider calling the manufacturer and determining if the coach is wired to do this.

Gary: I have been motorhoming since 1974 and was a service manager for 15 years. I have never seen or heard of a motorhome that did not charge house battery while driving.

ga traveler · 07-23-2013, 12:52 PM

Quote:

Originally Posted by R F S

As I get to know our new DP I now find that the house battery is not charging with the coach running. Is there any connection with the energy management system and this circuit? Engine batts. charge @ 13.8vdc and EMS shows coach to charge with shore or genset. I have 2 large solenoids in battery compartment , thinking one is to connect the 2 systems when chassis voltage is low. Other for house to altenator??? 2005 Four Winds Mandalay 40B C-7
R F S

Have you checked this after the coach has been running a while. Some coaches have a bird or other type of system that charges the chassis batteries first and then starts charging the house batteries after the chassis batteries are up to full charge.

Clay L · 07-23-2013, 02:19 PM

The second solenoid may be the Battery disconnect. If so they are usually an electrically operated mechanical latching type that consumes no power after switching. The switching is done by swapping polarity on the signal leads with a momentary center off double pole rocker switch.

The ALT solenoid (some builders use other nomenclature such as Boost) is a continuous duty solenoid which connects the engine and house batteries and is usually activated in two ways:
1) By voltage from the RUN terminal on the ignition switch
2) By pushing the ALT or Boost momentary switch on the dash.

It allows the house batteries to start the engine when the engine battery is down and allows the alternator to charge the house batteries.

The above info is for non-BIRD or BCC systems.

GaryKD · 07-23-2013, 05:40 PM

Hi ga traveler,
My friend has an HR (2004) 40' coach. Drove me nuts trying to figure out why the coach batteries were low when we arrived at a CG after a travel day. Had my friend call HR. They confirmed her that her coach does not charge the coach batteries from the alternator. They are charged only from the generator or shore power. Gut feel says there may be more coaches like this.

My first coach, 1978 Winnebago Brave bought new, did not charge the coach batteries from the alternator.

Note the OP says "EMS shows coach to charge with shore or genset".

ga traveler · 07-24-2013, 05:40 AM

Quote:

Originally Posted by GaryKD

Hi ga traveler,
My friend has an HR (2004) 40' coach. Drove me nuts trying to figure out why the coach batteries were low when we arrived at a CG after a travel day. Had my friend call HR. They confirmed her that her coach does not charge the coach batteries from the alternator. They are charged only from the generator or shore power. Gut feel says there may be more coaches like this.

My first coach, 1978 Winnebago Brave bought new, did not charge the coach batteries from the alternator.

Note the OP says "EMS shows coach to charge with shore or genset".

What a great design. If you are a dry camper, you would arrive at a campsite with low house batteries,(using the water pump and acc. underway) Further deplete the batteries at the campsite, and start out the next day with dead batteries. If you had no generator, I guess you could stop at Walmart and ask to plug in.

wjell · 07-24-2013, 06:16 AM

From a newbie, but learning every day.

I tend to agree with "not all coaches charge house batteries". One of the few manuals I got with my "new to me" HR details a "special alternator" upgrade that supposedly will charge both. I also see a disconnected alternator down in the basement that has probably been there for decades. My guess is that it was replaced by the "upgrade".

All conjecture, but seems logical.