Help with Electrical

Dreamweaver wrote:

westend wrote:

Haven't figured out where the converter is yet. Been reading through a bunch of info and poking around my rig - still haven't found it.

Typically, the converter will be installed below the load center, behind a faceplate. You don't have to find it to see if it's operating, though. Measure voltage across the house battery terminals when connected to shore power. You should measure above 13.2 V.

The latter part of your post above, quoting the Xantrex and switch user, refers mostly to his poorly operating inverter/charger and the workaround of using a disconnect switch. Don't make other folk's anecdotal system idiosyncrasies your own personal problem.

Please forgive me on this, but it doesn't make sense. I am not a mechanic, but I can do a few things.

What doesn't make sense is this:

You said in essence that if I connect the RV to shore power, and measure across the battery terminals, 13.2v measurement will tell me whether or not the converter is operating properly. Is this correct, or am I missing a piece of the puzzle?

That is absolutely correct, 13.2 V or greater in measurement will tell you that the converter is sending charge power to the battery. It does not affirm that your converter is adequately charging the batteries. If you can find the converter and list the model number, folks may be able to tell you if that converter is known to do a good job of charging. Not all converters are equal. Some operate through all three stages of charging well and some don't.

In your specific case, where there is an isolation problem between the starting/chassis battery and the house batteries, you have an additional issue. If the house batteries are low and there is no isolation, the house batteries will draw current from the starting battery until all batteries are at the same level.

The links I posted earlier in this thread explaining 12V systems should give you a clue as to how your 12V RV system works.

I think one of your issues with the diagnosis and repair of your 12V system, is that you are trying to coordinate what happened before between the shop's repairs and the current problems you're having. Every few posts, you harken back to the sequence of events. In the technician's world, prior events can be helpful but is not a total indicator of the issues. An independent diagnosis and repair is where you should be focusing, just like the technician encounters when you first roll into the shop.

To help you get over the shop repair cause syndrome, maybe this sequence of events will help:
You roll into shop with repairs needed. Unknown to you is the condition of any battery in your RV. They may be fully charged, they may be half charged, they may be beyond hope (as you discovered). The repair folks proceed with your repairs using the house battery system to run lights, pumps, thermostats, blowers, circuit boards and the alarms. Repairs are completed and the RV is somewhere in this schedule, connected to shore power. All of the batteries in this RV are now drawn down to there limit. Further, the isolation relay between the starting battery and house battery has failed so you now have at least three(?) batteries that are drawing charge current from the converter. Mr. converter is unable to produce this power and blows a fuse. You now have no 12V charging and low batteries.....or....the draw of all three batteries is above the threshold of the main 12V circuit breaker and it trips. The result is the same, no charging and depleted batteries.

Check that converter output! You do have a meter in hand, correct?