2002 PT Cruiser will not hold charge.

My first thought is alternator but sounds more like an electrical issue, either something is staying on causing the battery to drain obviously --

Try disconnecting the negative terminal on the battery and connecting a test light , clamp one end to the battery terminal and the other to the cable ...with all the doors and ets closed and switches off does the test light light up, it's so you have a draw in other words an open circuit something is not closing all the way such as a switch could be the glove box, courtesy lights, trunk light, or the light under the hood. You will need to pull each fuse while holding the door switch closed until the light goes out ..this will tell you what light is causing the draw ..if one is the cause ..otherwise i believe it would be worth having a good mechanic look into the issue

It sounds like you have a bad diode trio in the altanator. to test remove the belt off the altanator then turn the key on and see if the fan on the altanator spins if it does thats your problem. If not then get a 12 volt test light and remove the negitive battery post and put one end of the lead on the battery and the other on the cable. with everything off does it light up? Yes? then make sure the glove box light is not on, or remove it for a few days and see if the problem goes away if it does you have solved your problem. you can test it with the glove box light out with the test light. If the light stays on you can pull one fuse at a time to see if you pull a fuse it goes out. if it goes out with pulling a fuse then you have found the problem with the circut giving you the problem, after you loctae the fuse take it to a shop and tel them the fuse that stops the light from being on. If you need more help post here.