Just came into possession of a 1970 Safari. Electrical has been updated it appears. New Coleman AC. Plugged up to my house (20amp) using a regular orange extension cord. Only ran the AC and turned a few light on and off. All was well. A few hours later interior lights not working. AC still runs. Any ideas as to what may have happened? Probably obvious but I'm no sparky.
I'm not familiar with the specs for the Coleman AC unit, but I would be surprised if 20 amps (and your extension cord could actually be a 15 amp cord) is sufficient. After you've replaced all the blown fuses, I would try to run the AC when connected to a proper 30 amp power supply. Note that a residential dryer outlet does not have the proper power to run your trailer even though the plug looks compatible. Plugging a RV into a dryer outlet and frying the RV electronics is a tragic newbie mistake. Don't do it! Go to a campground to test this.