encrypted drive not prompting for password

Then there must be an entry for it in the keychain somewhere. That's the only place the password is saved. When I saved the password to the keychain it unlocks the encrypted drive automatically and mounts it.

Open Keychain Access click on the Login keychain on the left sidebar and search for the name of the disk volume. You should find the entry and you can delete it. Then eject the disk and re-insert and it should prompt for the password. Do not check the Remember in Keychain checkbox if you wish to manually type the password to mount the disk.

Is the disk still mounting? You can access the contents of the disk?