The exhaust fan in my wife's bathroom went out and I have never attempted to fix one. I cleaned it real good and made sure the fan could move freely but I am guessing the motor died on me. Do I just need to take it down and take the motor off and replace it? Do hardware store, Lowe's, Home Depot etc. carry replacements?
The fan/motor assembly usually removes easily from the metal housing. There is usual only one or two screws and the plug to remove it. How available replacements are depends on the model. Big box stores stock some, but contact the manufacturer for availability and location of distributors.
There should be a make and model # on the housing somewhere. I'd check to see if it was worth the money to replace a low end coffe grinder sounding fan. Most bath fans I've come across are low end units begging for an upgrade.
I'll second that Ron. Most of the one's I've put new motors into the old fan box, I've had to come back within a year and replace the entire unit with an upgrade, and thought "I told you so". Spend the monies now, or spend it twice. David