buzzing noise from inside trike on hot day

[prowell4]

After riding my trike on a hot summer day in Tucson it will make a buzzing/humming sound like a small fan is running after it has been turned off. It is not the main cooling fan. I have taking the side chrome off and can not see any smaller fan. Does anyone have an idea what this could be?
Thanks

 

[Gorilla]

After riding my trike on a hot summer day in Tucson it will make a buzzing/humming sound like a small fan is running after it has been turned off. It is not the main cooling fan. I have taking the side chrome off and can not see any smaller fan. Does anyone have an idea what this could be?
Thanks

Can you give us a hint on what your trike is? Make/Model/Year

 

[greenSEtrike]

my GL1500 motor trike doe's that some times, it's buolding pressure in the gas tank.