inside lights dim

[str8shooter_mn]

I just replaced the coach batteries, 2-6v deep cycle. We are plugged into shore power. After a while our inside lights get very dim. Disconnected converter and checked out put. It is at 13.62 VDC as manual says it should be. Lights get bright again after starting coach. Running off of alternator Voltage.
What am I missing? Is there a relay somewhere that is supposed to switch from alternator to converter power to charge batteries when coach is turned off? Old batteries were shot, wouldn't take a charge.

[DutchmenSport]

I had something similar happen to my 5er a couple months ago. Lights got dimmer and dimmer and dimmer. Everything checked out just fine. Couldn't figure it out. What I failed to do after we returned home from the week-end trip when this happened was .... well.... (do I really have to admit this ... well OK, if it will help you) ... I forgot to flip the breaker on at my RV electric box!

The residential refrigerator was running of the inverter for quite a while, drawing down the battery, making lights go dim after a few hours. DUH!

Check to make sure you flipped the breaker back on at your power pole! It might be just that simple.

[str8shooter_mn]

Thank You all for your input. After further investigation, find that the converter is faulty. Have new one ordered via amazon.

[cavie]

You changed the batteries.
That's the place I would start. There are 2 30/40 amp reverse polarity fuses on the converter. There may be an in-line re-setable fuse near the batteries.

[cavie]

You changed the batteries.
That's the place I would start. There are 2 30/40 amp reverse polarity fuses on the converter. There may be an in-line re-setable fuse near the batteries.

[cavie]

You changed the batteries.
That's the place I would start. There are 2 30/40 amp reverse polarity fuses on the converter. There may be an in-line re-setable fuse near the batteries.

[dougrainer]

str8shooter_mn wrote:
Voltage before changing batteries was 11.3 volts after 3 hour charge at 10 amps. Batteries were disconnected during charge.
Voltage of batteries after replacement was 12.5 VDC with converter connected

Either the Converter is bad or there is a fault in the charge wiring from the Converter to the batteries. Doug

[str8shooter_mn]

Voltage before changing batteries was 11.3 volts after 3 hour charge at 10 amps. Batteries were disconnected during charge.
Voltage of batteries after replacement was 12.5 VDC with converter connected

[Ivylog]

Dim lights = low voltage = charger/converter not charging. No load voltage of the converter doesn’t tell you much...what’s the voltage when hooked to the batteries?

[ArchHoagland]

Was it working OK before you changed the batteries?

[Flute_Man]

With everything hooked up like before with the lights dim I would make that same voltage test. Please let us know what the results of that voltage test are.

[ScottG]

Absolute classic sign of a dying converter.

[str8shooter_mn]

Coach is a 2011 Fleetwood bounder classic 36R on a workhorse chassis. Has a converter WFCO WF-9800 series, 65 AMP

[enblethen]

Many Class As have a charge relay that enrgizes when the coach is running. This is to charge batteries.
Do you have an inverter/charger or a converter? Make and model?
You could have a loose connection causing lower then normal voltage from the batteries and the inverter/charger or converter.
Make and model would be beneficial!

[DFord]

It would be most helpful if you show the year and model of your MH. Without any of that, any answer you'd get would be a guess.