Is it normal for XBox360 one cooking fan to work with the dual fans?

While working on the 360, I noticed only one fan of the dual fans was working. Curious if that’s normal or not? I test the fans with giving them power and both work, also tested power output and both being power, and also stopped the good fan from running to see if the second fan would turn on but it did not, unit shut down due to heat. Anyone have any thoughts or experience with this issue? Thanks