burning rubber smell

There are two places the blower motor can pull air from. The cowl (the black trim at the base of the windshield typically where the wiper blade arms are connected) as well as the dashboard on the interior of the vehicle when the climate control is set to "recirculate". If you have the climate control on recirculate and the smell is not there or very faint but on the setting to pull air from outside is very noticeable the smell will be coming from the cowl or engine bay. If you open the hood while the engine is hot and running and you can smell it, the problem is in the engine bay. If reversed the smell must be coming from the vehicles interior. If the smell does not change this could be your cabin air filter. The filter is usually located very close to the blower motor (behind the glovebox typically). If you haven't already, change the filter with a charcoal filter. This will help significantly with any smells being introduced into the cabin. You can also find out if you have any mice hiding food or mice in general stinking the place up. Lastly another common smell is bacteria growing on the AC condenser. To fix this, put the blower on high and spray any common household disinfectant into the cowl at the base of the windshield (spray liberally). This will coat the condenser and destroy the bacteria. Plus your car will smell like lemons. If the engine bay isn't stinky start with a cabin air filter (charcoal) then proceed to the disinfectant. If you replace the filter yourself wear gloves, mouse poop and dead critters are common. Hope this helps!