failed java install

Tried to roll my 2013 macbook pro 13" back to Java 6 so I can run IDE for Arduino but I have messed this up. I was left with the java icon in system preferences not working, so found out how to delete this. downloaded and ran the Java 6 install which went through to the end and reported that it was installed. I still do not have a java icon in the system preferences, and my IDE software reports Java missing. also did the online java test and it failed. Not sure what to do next. Im running the latest OS X. Does anybody have any suggestions?