Jump to content

Engine Batteries not being charged by shore power

Tom Rosenbaum
Go to solution Solved by Tom Rosenbaum,

Recommended Posts

My 2005 Holiday Rambler Ambassador engine batteries are not being charged by shore power or by the generator. When I bought the unit new it was not set up to charge both sets of batteries.  In 2010, I installed an Intellitec Isolator Dual Delay Relay to charge both sets of batteries. Worked great till this past week when I saw that the engine batteries are no longer being charged, except by running the engine.    Looking for ideas on how to fix it.  Thank You.


Tom Rosenbaum

2005 Holiday Rambler Ambassador

2022 Jeep Wrangler

Link to comment
Share on other sites

Get a voltage measurement on the relay that combines the batteries. If the large post are not the same voltage, obviously they will not be combined.

Then measure the voltage on the small terminals. You should have 12 volts on one post and zero volts on the other. If you have these voltages the solenoid should be engaged and the large terminals should be the same voltage. It is common for the solenoid to go bad. Post a picture of the solenoid if you have any concerns or doubts. 

Link to comment
Share on other sites

59 minutes ago, Tom Rosenbaum said:

The solenoid was bad.  It was replaced but the problem exists.  Looking to replace the Isolator Dual Delay Relay. Anyone know of where to find one?





Not arguing with your information, however, when most folks install a BiRD or BiDiretional system.  They use a “Big Boy” solenoid,  Monaco started to switch over.  Memory says it was the 200A Big Boy.  Google it.  

If tHe 2008 did not have a BiRD syatem, then the BiRD  Diesel 2, was needed. This is what mine, with the Factory 200 A Big Boy has.


There is NO NEED, and Monaco dropped this in the Camelot’s in 2009 or maybe earlier, for the GENNY signal.  You just use the 4 terminals.

NOW, if you need the full schematic, which also shows how the Boost is hooked up….fine.  I will PM the print.

Be AWARE.  If you had a 100A Big Boy….then it is OK for continuous 12 VDC.  BUT, if you have a 200A, like the picture, it AIN’T.  The BiRD Diesel 2 sends out a “pulsed” 12 VDC signal.  So, think of it as “turning on and off….” Say 20 times per second. That means (1000 divided by 20) that the Pulse Width or time ON is 50 Milliseconds.  So, if only on for 25% ….it is on for 12.5 and off from 37.5….forget the “cycle time”.  Then, put a VOM on the control contacts….you will read 3 VDC.  

Now, the “simple” check is.  Do you have around 3.2 to say 5.0 VDC.  IF SO…ALL IS WELL.  You need a lab setup to see the percentage ON….SO, IT looks like the are lowering the voltage.

If whatever you added is NOT a BiRD Diesel2….and was a full 12 VDC and have a 200 A Big Boy, the coil failed.  A NEW ONE will fail.

Thats how it works.  Post a picture of what you added.  If you download the instructions for the BiRD Diesel 2, it shows the schematic.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...