99 silverado and 99 tahoe leak water on floor passenger sidewhen using a/c any help? truck leaks some when in rain. no rust on either. thanks....

 

first,you have to establish it IS a/c water...if it is..

look under the hood and make sure your "boot" is there..its a rubber,90 degree boot on the drain..it prevents wind rush from blowing the a/c water back in the case.

you can slip the boot off,and blow air in the drain to try to unclog it...

if its not clogged,and the boot is there,AND its a/c water....about all ya can do is remove the hvac case and reseal it