I have a 1995 geo prizm and someone stold my radio, cutting the main wiring harness. I can't figure out the wiring and the new radio i tryed installing only comes on when i first start the car. Can anyone help me, please!

Sounds like you need to find the constant feed wire in the factory harness. This is the Memory wire. Connect a test light to ground and probe the wires with the key off. The one that lights the tester is the constant feed. This gets connected to the radio as well. This keeps the memory alive so the clock and pre-sets remain intact when you turn the car off. I don't know what type of radio you have, but, most of them I have seen have a small 5 amp fuse in the wire and most I have seen have been orange. The radio owner's manual should identify this wire. Good luck.

Steve