i have a 2005 chev monte carlo lt it has keyless entry. when its is cold the keyless part does not work. after it sits in the sun for a while then it works ok also the raido is very low after it is cols but after it sit in the sun for a while it will play loud. what could be the problem

That's highly unusual, for systems like that to be temperature- dependent. I can understand if the battery is weak and those accessories don't work very well with the engine off but improve when it warms up, but with the car running and everything getting power, it's hard to say. I've seen cars do *very* strange things though when the alternator is about to go out or is putting out no voltage and causing the battery to discharge. In my personal car on my way to work one morning, the radio shut off on its own, then my lights started dimming and the engine began stumbling. I barely made it to work and it wouldn't start when I went to pull it into the shop to replace the alternator.

of course....the system ground is weak...cannot find the brain of the lockin' system...and the battery is older than five years old...meaning it can no longer take a charge fully....SO...get a NEW battery and clean the main ground connection from the black 1/0 cable to the fender/frame....wirebrush the lug and spot where it attaches....use a pliers to hold the lug so that you do not break it~ put them together for a BRAND NEW car~!

EDIT: If you ARE talking about those accessories while the car is sitting, with the engine OFF, then chances are good that you either need a good battery terminal cleaning, or a new battery itself.