My Jeep won't turn on....I've changed the battery,Turned key tiimes to accessories and got code p0700 then it showed done. When I turn the key in the ignition everything lights up as normal but then gauges(fuel gauge goes up to almost fill and goes back to empty, the odometer does the same and after a bit the engine light comes on and stays. help if I can.... Thanks in advance!
P0700 refers to a fault within the transmission control module; the module must report that the transmission is in "park" (or, perhaps, neutral) for the starter to operate.
However, the error message disappears, which may indicate that the fault was present at some time in the past, but is not present now. I don't know enough about your car's system to guess.
Bad connections from the battery to the car, or a slightly-tired battery can yield "the dash lights up but starter won't crank" symptoms too. Make sure the battery is good by load-testing it, which will assess it's ability to deliver enough amperage to run the starter, or whether it can deliver only enough the light up the dash. Remove, clean, and reattach both the battery positive and negative cables at both the battery end and the far difficult-to-get-to ends.
If the battery and its cables and connections are good, you'll need to investigate both the starter to determine if it's operative, and perhaps the transmission control module to see if it's faulty and preventing the starter from operating.