The AC system may blow warm air due to refrigerant loss caused by a leaking low pressure AC hose. These hoses commonly develop a leak at the hose crimp connection.Google+
Car Problem Reports
Nissan Altima Low Pressure AC Hose May Leak at Crimped Connection
Nissan Altima Problem
Average Mileage: 101,064 mi (18,000 mi - 200,000 mi)
Heat works only when moving and air conditioning blows whatever temperature is outside
Visitor, 2005 Nissan Altima, 95,000 mi
A/C not cool. Replaced pressure hose.
Visitor, 2002 Nissan Altima, 58,000 mi
Both hoses are leaking...
Looks like a tiny pin prick hole near the crimped area.
Visitor, 2006 Nissan Altima, 73,000 mi
a/c hose gone bad
Visitor, 2003 Nissan Altima, 67,123 mi
Ac problem, hat air
Visitor, 2000 Nissan Altima, 125,000 mi
Low pressure AC hose leaking. Still waiting for it to be replaced.
Visitor, 2005 Nissan Altima, 33,000 mi
replaced pressure hose...$400
Visitor, 2005 Nissan Altima, 105,000 mi
A/C Low pressure line leaking. Estimate cost to fix 350
Visitor, 2005 Nissan Altima, 48,000 mi
Leak detected at front connection using blacklight detection.