2005 Mercedes-Benz C-Class air conditioner

2005 c230… AC compressor comes on when “AUTO” is selected (MAX air setting), but the fan that blows the cold air into the cabin does not come on…this is an intermittent issue (sometimes it comes on, other times not). Checked the coolant pressure and it is the “blue” range of the gauge, indicating that the system is well charged. What might be the problem? Thanks!

Maybe the blower motor has a problem or the regulator that controls it.