Backup lights stopped working or work every once in a while, sometimes it won't start in park, so have to put it in neutral and push the stick a little forward. The heater a/c fan won't turn on sometimes and every once in a while my stero will go to protect mode when nothing has happened. Any suggestions

 

search NSS cleaning for the reverse lights and starting issue

 

This will explain how to remove and clean the NSS:> http://go.jeep-xj.info/HowtoNSSrebuild.htm

 

XX2 on the article ol"blue showed you for the NSS(your backup light and starting in park issue) excellent article.
"..The heater a/c fan won't turn on sometimes.." Can you elaborate on that a little? These Jeeps have a blower motor resistor which controls your fan speed. Usually when they burn up you lose 'low speeds'.. 1,2 etc.. but even if it's toast, the HI position will work normally, as it's not wired thru the resistors. As for the radio, I have no idea. Post again with more details and we'll try to post more ideas.