House battery charging

[John Solis]

I have a thor 31E class c motorhome that is only getting 7.5v to charge the house battery. Does anyone have an electrical diagram that shows the charging circuit for this RV? Any suggestions?

[HaRVey]

You can call Thor customer service and give them your VIN and they should be able to send you a diagram, or you can try their support page, which I've been told has specs and drawings available -
https://www.thormotorcoach.com/owner-resource/

[John Solis]

Thanks HaRVey, I appreciate the help.

[cavie]

Originally Posted by John Solis

I have a thor 31E class c motorhome that is only getting 7.5v to charge the house battery. Does anyone have an electrical diagram that shows the charging circuit for this RV? Any suggestions?

start by checking the output voltage of the converter or the inverter/charger. don't need a diagram to do that.

Is the 7.5 battery voltage or charger voltage? Either way it's dead batteries.

[GTM41261]

Along with checking for inverter voltage. Also check the battery connections are they clean and tight. Are your grounds tight and clean? How old are the batteries?

[gmc]

Originally Posted by John Solis

I have a thor 31E class c motorhome that is only getting 7.5v to charge the house battery. Does anyone have an electrical diagram that shows the charging circuit for this RV? Any suggestions?

The ‘charging circuit’ is pretty simple,
You have either a converter or inverter/charger (just called converter below for simplicity)
With shore power or genny running, and use/store in ‘use’, the converter charges the coach batteries... and in many cases (class A Ford chassis) also charges the chassis battery.

Simple check with voltmeter...
Disconnect shore power, genny off, use/store in ‘store’
Read voltage at batteries - should be 12+...
Plug in or start genny... leave use/store in ‘store’
Read voltage exiting converter(or anywhere on 12v bus on coach side of use/store. - should be 13+

If batteries read 7,5 - time for new batteries...
If converter output reads 7.5 - time for new converter...