I turned the air cond./heater on and a dead animal smell is in the vent system.

Ew... That's gross... a dead rodent in a vehicle, how terrible!!!... Lucky it didn't eat the whole dash out of it!

I found the dead mouse when I pulled the blower motor out. It built a nest which is hard to believe since we use the vehicle often. Cleaned it with bleach and water and neutralizer . Thanks for your help everyone.

Don't mean to jump ahead here but with cooler weather coming... This usually gets worse as the engine stays warm a good while after parking for the night... They love that!... Try to get rid of them anyway you can... I've seen lots of damage to vehicle wiring and rubber components from these critters (pest) costing the customer hundreds of dollars!