hi my battery light and other warning lights were coming on so i changed the alternator. then when i drove for about half hour no battery light but the security light came on and the stereo cut in and out and now the battery is flat its a new battery any help with what could be causing this would be appreciated. Its a 2002 tj magna wagon.
thanks

The alternator you put in - new, reconditioned, or just one from a wrecker?
Sounds like it isn't working.

If you've got or can get a multimeter, put it across the battery terminals while the engine is idling.

If you've got a reading of around 13.8V your alternator is working.

If you've only got around 12V (or the same reading as when the engine is not running) your alternator has gone to god.

its from a wreckers thanks for the help

ill buy a multimeter tomorrow to test.. thanks for the help

its from a wreckers thanks for the help

Thought so. The alternator in my 2nd gen gave up (this was years ago) and I did the rounds of wreckers to find one. Located one 12 km from home, picked it up and put it in. It was not working. Took it out, went back, exchanged it. Same story with this one.
Gave up and had my original one rebuilt.
Lesson learnt. Rebuilds from now on.

hi guys thanks for your help.. The alternator i got was dodgy..i got another 1 have installed it and everything is where its meant to be on the multimeter im hoping problem solved,,