Z-24 air conditioning problem

i recently baught a 2000 z-24 and the compresser didnt work so i replaced it its running fine but it seems like there is to much pressure on the low end of the system any ideas what would cause this? what should the pressure be normally? also neither of the back speakers work anyone know any tricks about this? and finally the fog lights dont work im hoping its just some burnt out bulbs the indicator light on the switch doesnt come on at all! thanks for any help you guys can give me!