I am Michael I have a Icom ic-718 the fan...

hi,

it is better for the unit to have the fan continuous in running, however if you wish to have it on automatic , you may need to check the driver transistor of the fan, it is definitely shorted electrically.

most of the amateur radio operators I've known even add blowers to their unit specially during modulation with other operators and have it turn on continuously even when monitoring only.

it would be much better if you focus your attention to the antenna system than the fan, it would be worth doing, have fun!

just remember a good antenna can take you further than you can imagine! just as long as you have a very good SWR.

hope this helps, thanks for using Fixya!