If you are referring to the 12 volt accessory plug, like the one you may have in your Winegard antenna booster, it is probably rated for a MAXIMUM of 7.5 amps 12 volts DC.
12 volt DC amps and 120 volt AC amps are different animals.
Here is the Winegard spec sheet and warning:
http://www.winegard.com/kbase/upload/2451486.pdf
WARNING: Do Not Connect High
Current Devices to +12 Volt Receptacle
on Wall Plate/Power Supply.
Maximum current ratings of
this receptacle is 7.5 amps at
+12 VDC.
If there are other 12 volt accessory plugs in your RV (not in the Winegard antenna booster plate), they may be a little higher rated, as Youroo showed. You may have a fuse in your control panel that controls it/them.....and that will be your max 12 volt DC amps for it/them.