left side fan does not work MacBook Pro2017

Hi,

If you have a 13", I believe you have only one fan. If you have a 15", bring the Mac to an Apple Store “genius” bar for a free diagnosis and free repair (or refund/exchange if you're within 14 days of purchase): https://support.apple.com/contact

incorrect. the first generation of 13" retina display MacBook Pros had only one fan, but the newer thinner MacBook Pros with USB C have 2 fans regardless of size. it sounds to me like one of your fans doesn't work

What model of MacBook Pro?

Good to know. Thanks.