Air Conditioner-98 Ranger

I have a 98 Ranger 4 cyl. standard with power steering and air.The blower comes on but not the compressor checked freon switches and freon all ok and all fuses can hear relay under hood switching and have swapped relays no differance there are two diodes in same fuse box under hood switched out both ok.There is no voltage at compresser . can some one help me?