99 navigator front blower mtr wont turn on

When you say "along with other functions" do you mean the dash climate control is dead?
If it is dead then it could be a fuse. Then one for that on a Navigator is under drivers dash.
If the temp display is there but no fan. Then it could be bad/stuck blower motor. It is under hood on passenger side near firewall.
You can give it a few good taps and see if it comes on.
A better way would be to pop the two wire power connector off of it and test for voltage when you set the inside to be on with engine running.