Ac blows when driving down the road but not when idle. Does it just need charged?

blower /fan relay..all connections..test fans seperately..

make sure the cooling fan is working if so the freon charge could be low

In this type of situation you must have the AC system pressures tested to make sure the system has a full charge. A low charge can cause these types of symptoms. You will need a set of AC gauges to do this test, about $50-$100 depending on brand and quality

you need to flush raiator

Replace the alternator,it is not charging like it is supposed to.It should read at the battery with the engine running ,and head lights on,and ac on high blower motor setting,13.65 volts,to 14.25 volts,no less.also slow charge the battery to get a deep full charge,cause it will be low .

Low charge of freon or overcharged. Also lack of electric fans running at idle decreases air across condensor making it hot.

It could be a number of things. Check to see if the clutch is turning on the compressor. If it keeps turning on and off (cycling) it is low on freon. Is the condenser clean and free of bugs and road debris? Is the radiator fan coming on? If not that could explain why it is cold while driving, but hot while idling. Most all vehicles will blow colder on the AC when driving down the road because you are getting cooler air through the condenser. Hooking up a set of gauges to the vehicle will tell you best what is going on. Basic rule of thumb is: low side should be in the 30-40 lb range while running and the high side should be around 100 lbs higher than the ambient air temperature. Anything drastically different means you have a problem.

It might be low on charge

1'st check to see if the a/c belt need's to be tightened,if tight have your ac pressure checked.hope this helps,

your vehicle is under warrenty take it back to the dealership. they should fix it at no charge.