Converter problem???

[Indy Itasca]

Before I call the dealer and make the dreaded service appointment could someone please confirm my thinking.  We've had this coach since Monday and are still outfitting it.  (2007 Sunrise 35L). Today I noticed the house batts were at 12.3 volts. I fired up the genset to charge the batts.  I had good AC from the gen but the house batts were still reading 12.3  I checked the converter and it did not appear to be running, no fan, no hum, etc.  Breaker for the converter was not tripped. I pulled the plug for the converter and have 120V AC at that outlet.  There are 2 car type fuses (30A) on the converter and they both tested good.  I started the engine and the house batt volts went to 13.6 which is the output of the engine alternator. The only other place I can think to look would be the fuse-able link in the batt compartment, but if the link is bad wouldn't the converter still run, just not charge the batts?  Any thoughts?

Bruce
     

 

[Just Lou]

Bruce, I think your logic is sound.  However, the converter may be running even though it's not charging the batteries.

Do you have the house battery disconnect switch on? or off?  Most coaches require it to be on to charge the house batteries.

If the converter is truly "not running" then switching the disconnect off while plugged in should kill all interior power.

If you determine that the converter "IS" running there are things to check to isolate the non-charging condition.

 

[Indy Itasca]

Thanks Lou, yes the house lights were working, IE the batts were not isolated or disconnected.  I could not see anyplace to measure output of the converter.  The coach is under warranty so its not a big deal, other than giving it to the dealer for an indeterminate amount of time while they stumble through it. I always feel that the more I can do to isolate the problem for them the smoother things will be, but that's probably wishful thinking on my part. 

 

[Just Lou]

Bruce, try this:

With both the shore power and generator OFF.  Turn on an interior light. 

Now, flip the battery disconnect switch (yours may be on the dash.  Mine is on a wall).  Do the interior lights go off?

Now with everything in that same condition, plug in the shore power or start the generator.  If the lights come back on, your converter is working.

Off the top of my head, I can't think of another way to quickly test it without a meter.

 

[Indy Itasca]

I'm not smart enough to know for sure but I think your Bounder is wired differently than my Sunrise. I believe the genset is wired to the house batt. I don't think I can start the gen with the house bat disconnected.  I'll pull the wiring diagram and check.  Do you know if the converter is working is the cooling fan running all the time, or does it only come on when needed? THe fan isn't running on mine at all.

 

[Just Lou]

Unfortunately yours is wired like mine.  I can't strart my generator without the house batteries either..  You might be able to fake the system out if you press and hold the aux start switch while starting the generator.

Don't you have an adapter available to attach the shore power cord to an available 120vac outlet?

I suspect that since your converter won't charge the batteries that it is not drawing enough current to heat up to the point of needing the cooling fan.  Most fans are on an internal thermostat.