Originally Posted by JackMroz
Well I went and checked my battery and its hooked up as it should be. I ordered a new 45 amp converter today as the one in my coach screams when its plugged in. I suppose its just worn out and wants to retire. I have not had time to do all the great suggestions to my 12 volt problem but I'm hoping to get some time on Saturday. I'll keep you all posted....
It is probably a good idea to replace it if it is loud. Mine is pretty much silent, except for a fan the runs sometimes. But even then, it is not very loud.
Once you have the new one installed. Leave the trailer unplugged for a minute and measure the voltage on the DC wires attached to the convertor. Fully charged you should see 12.7V or so. If you read significantly less that this, then either your batteries are not charged or you have a bad connection to the batteries. Take another measurement directly on the battery terminals, they should be very close to the same reading as you got on the converter.
Now, plug in the trailer to AC. You should see the voltage rise to something > 13V, depending on the charge state of the battery. After it charges overnight you should read >=13.2V on both the battery and the connections to the converter.