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becks · 03-19-2014, 11:19 AM

Asking for help for a campground neighbor who does not have computor skills. He has a 03 Dynasty and his chassis batteries read 12.6 and coach won't start. He is plugged in to shore power, and wonders if it should be reading much higher. Batteries are dated 2007. I plan to remove and clean his posts and cables as a start. Thanks in advance for any help.

**TonyDi** · 03-19-2014, 11:32 AM

Does the starter engage? Does it crank but just not start. Will genny start? If so let it run for a bit and try again it should help with cranking power.

becks · 03-19-2014, 11:38 AM

Starter does not engage, just clicks.

**TonyDi** · 03-19-2014, 11:49 AM

Typically what happens when a battery is low. Did you try starting the genny? Does it have a battery boost switch? If it does try that and see if you get enough to start.

**TonyDi** · 03-19-2014, 11:51 AM

If you have a battery boost switch try that and see if you can start.

Lee0920 · 03-19-2014, 02:33 PM

You said that he is on shore power,,then the house battery's should be full and the boost should work, sounds like something is not charging the battery's, put a charger on the chassis battery's.

wb7auk · 03-19-2014, 02:37 PM

Sounds like dirty connections

becks · 03-19-2014, 02:46 PM

Coach did start after I cleaned some dirty connections for him. He now wants to monitor his chassis batteries, and asks what they should read on any given day for voltage. He wants to know from other Monoco owners if they should read from 13.1 to 13.4 when he is hooked to shore power?

gruelens · 03-19-2014, 02:51 PM

When plugged in to shore power, chassis batts should read at least 13.2 v ...... a reading of 12.6 is a resting voltage of batts that are not online with an active charger ........ 7 year old batts may not have enough reserve to crank engine ....... hold batt boost switch down for at least 3 minutes, then try cranking engine while continuing to hold boost switch down

becks · 03-19-2014, 03:14 PM

Thanks gruelens, that is what we thought, as I shared with him that mine always read between 13.1 and 13.4 on any given day while plugged in and thought his should be the same.

wb7auk · 03-19-2014, 04:02 PM

As stated when the chassis batteries are under charge they should read at least 13.8
volts the real question is does his coach charge the chassis batteries when on shore
power? A lot do not

Eddie Foy · 03-19-2014, 04:05 PM

Quote:

Originally Posted by rebootsemi

You said that he is on shore power,,then the house battery's should be full and the boost should work, sounds like something is not charging the battery's, put a charger on the chassis battery's.

More than one battery is batteries, not battery's.

Mike Canter · 03-19-2014, 04:43 PM

I am pretty shore that the 2003 Dynasty has a B.I.R.D charging system with a Big Boy relay in the Rear Electrical Box in the engine compartment. This BIRD system is what charges the chassis batteries when plugged into shore power or on the generator combined with the inverter/converter. Also I believe he is probably looking at the chassis battery voltages on the Aladdin System which is on the engine page and the ignition key has to be turned to the first click to read the correct voltage. To read the true battery voltage the MH should be unplugged from shore power without the generator or engine running. A fully charged good battery should read in the 12.6+ volt region. It should read up around 13.2 to 14.2 volts if the battery is being charged by the BIRD from shore power or generator and also high 13's to low 14 volts with the engine running. The most common problem with chassis batteries is that the battery cables get corroded. The battery should be cleaned with baking soda and water mix and a stiff brush then hosed off. Then buy a battery post brush from an auto parts store and remove the cables and dip them is a solution of baking soda and water again then use the battery post brush to clean inside the cable connector and the battery post until they shine. Most likely these are maintenance free batteries so the water level inside should be good. Do both positive and negative cable. When all is clean then let the system charge overnight and check the voltage levels in the morning without shore power and again with the motor running. If the voltage is low on shore power but good when the motor is running then most likely the Big Boy Relay is corroded. If it is then I can give you instructions how to take it off and clean it. It is pretty easy and will take you about an hour to do.

This chart should answer your questions on battery voltages