no power to 12 volt battery with shore power'

Do you have a battery kill switch turned off?

Nevermind, I misread the OP.

I'd go with the kill switch.

I agree with kill switch. 13.6 Volts is charger voltage. A battery will read about 12.7 volts by itself.

What kind or RV?
MH have battery disconnects
Travel Trailers and fifth wheels have a circuit breaker or fuse near the battery(ies).
Many RVs all types have a fuse in the battery control center commonly marked BAT

13.6 volts is absorption voltage for the WFCO 8735. If you measured that voltage at the battery then the WFCO 8735 is working.

Do you have a battery disconnect switch? Large red handle? If handle can be pulled out then battery is disconnected from load center. And 5ers, if that is what you have, do have battery disconnect switches. Maybe TTs also.

This is what I have in my 5th wheel:

Some RVs have an auto reset circuit breaker in the line from the battery to the fuse block. These have been know to go bad. They are available at any auto parts store.

Wurtzberg wrote:
Battery reads 13.6 volts, when connected to shore power WFCO 8735 is not sending power to battery.

I have 12volt for lights when on shore power but no lights when boon docking

Many Thanks for any suggestions

ARE you measuring AT THE BATTERY? or at the indicator panel. (Panel measures converter out..

If you have 13+ at the battery then the WFCO is sending power to the battery for the battery resting voltage is less than 13.

WFCO's are noted for not going into BULK
Suggest a Progressive Dynamics

IF the WFCO is an intergrated power distribution center/converter the 4600 series IF its a stand alone box. 9200 series. try to match the last two digits of the model as close as possible.