I installed a new A/C compressor and hoses on my '90 ex-USFS Bronco (302, 5 speed). The cold air is great but it smells like an out of tune engine (sharp acrid smell) when it's running. The exhaust out of the tail pipe has the same smell. My research says the typical smell for a rejuvinated A/C system is a musty smell so I'm sticking with the exhaust smell. Per my listening test the exhaust (OEM) system doesn't seem to have any leaks. What I'm wondering is where does the A/C draw air from when it's running - the fresh air vent system, from the cabin, or ?