my macbook air charger not working

First, can you please perform the following 2 tasks to see whether one or both of them resolve the charging issue?

1. Reset SMC by following the directions applicable to your MacBook here ➔ How to Reset SMC. If that does not solve things then-
2. Reset NVRAM/PRAM by following the directions applicable to your MacBook here ➔ How to Reset NVRAM/PRAM. 

If none of the above helps then see if you can get another charger to test with your MacBook Air. If that does not work either then you know that the issue is within your MacBook Air. If the different charger works then you know that it was the previous charger which was the culprit.

Axel F.

i had to replace my MacBook air adaptor 3 times since 2010. 2 by apple, the last one on amazon

the amazon one is solid state and better than the apple one.

but check to make sure the adaptor needs replacing by testing the voltage of the brick and magsafe connection plug.

hope this helps