Looking at the end of your power cord on your RV and wondering “Is that a 125V or 250V RV plug on there?” When a cord goes bad, or you want to replace a plug on your RV’s cord, it helps to know whether it is a 250V or 125V RV style plug. That way when you make a run to your RV parts store or online, you know what you need. Here’s a quick guide on finding the right plug type on your RV’s cord.
Generally on new RV’s you will only see three different AMPs: 15, 30, & 50amp. So go ahead and take a look at the image below and see which one matches the one on your RV. We even added a few part numbers there so you can search for our part to purchase if you would like!
As you can see it’s pretty easy. Generally the 3 prong RV power cords will be 125V power, and the 4 prong style RV cords will be using 4 prong! Now all you need is a little wiring practice. Psst…we have a great guide on testing your newly wired cords here as well: Testing your RV power cord continuity.
Conntek Power Solutions Blog 
Good to know!