Not Charging Batteries

[Floridatex]

I own a 2010 Raptor. Of late, it will not recharge the batteries. Starting about a month ago, the lights would dim every 15 -20 minutes and I would hear the power converter fan kick on. I even had the batteries tested. They tested low, so I thought I just needed to bite the bullet and buy new. Now....I am currently recharging them using an outside charger because all lights, refrig. etc. go out. After a recharge, the batteries are good for about 2 or 3 days of use. (I am living in it.) I have changed the fuse block (located in the battery area). I have reset the general power supply by turning off main breaker and then powering up. I have pushed the battery disconnect and turn them back on (by the way, I hear the power converter fan come on when I do this). I have looked for loose wires. I am at a complete loss and am not really comfortable with the local RV shops to make a cost effective diagnosis and repair. (2 new batteries are still cheaper).

[Festus2]

The problem may be due to a issue with the converter since, for some reason, it is not charging the batteries. It can be tested by using a multi meter and checking to see if it is putting out 13.6v DC to the batteries. The procedure for doing this is outlined in the WFCO Converter Power Center User's Manual (assuming it is a WFCO model) but I would not attempt this if you don't have the electrical "expertise" to check it out. There could also be an open wire between the converter and the RV battery but I wouldn't be poking around the converter and the circuits coming off that if you don't know what you are doing.

[SkiSmuggs]

If your converter is tests bad, bestconverter.com has a PowerMax Boondocker direct replacement board for the WFCO 8955 for $159. You can upgrade at the converter at the same time you fix the problem.
A temporary solution is a battery charger from Walmart with an extension cord plugged into a 15 amp outlet (not an RV outlet).