hi i'm from boston and need some help with the electrical problem i'm having with my 2004 grand j ...sometimes it looses all power , nothing works i the entire vehicle....then for no reason at all everything comes on and it starts normally...any ideas?

 

Grounds! Check the main ground from battery to engine/frame.

 

My wifes Chevy Malibu started doing this,but chevrolet has a senser that reads battery voltage and if it gets to low it disconnects the battery(this way you are supposed to still be able to start it if you leave lights on).Once you turn the key it reconnects. It had dirty terminals,cleaned them and everything was fine. I don't know if your Jeep has this or not, my ZJ doesn't.

 

definitely check your battery and its conditions, the symptoms you are relating are typical for a grand when one or theother is bad or about to go bad.

 

One of my buddies have experienced the same problem...
And they found out that it's caused by some battery related issue...

 

Keep us up to date on what you find!