I've replaced the trackpad and it's working fine, except that the fan is always at maximum speed and never stop or slow down as soon as the macbook starts, so it's kindy noisy. I tried to reinstall the old trackpad (which doesn't click anymore), and fan went back to normal.

So, even if i don't know how the two are related, the new trackpad makes the fan go crazy. I've tried all kind of reset, smc etc... but no luck. Any idea?