Yep, should have run off your vehicle. Either as LJAZ has said, you have a bad connector or or you could have a faulty converter (the 12v for the slide, awning, etc. has to pass through the converter) or your battery is "toast" (internal short or really "bone dry"). Many converters require a battery, with some amount of charge even if it is low, to be connected before it will pass 12v through to your trailer. Those types of converters use the house battery as a kind of "filter" for the 12v. The trailer actually uses the 12v from the battery while the converter is replacing it as it is being used... If the battery is new, and it accepts a charge while connected to shore power, then it is time to start trouble shooting the 12v path from the vehicle to the converter... Goody, now you get to go out and get a good (not expensive, but, a good one) VOM to add to your arsenal of RV tools