how do i connect a power amp to a factory ford stereo in a 2002 ford ranger?

a easy way is to replace the factory radio with an aftermarket one that has a remote and rca connections. if this is not an option, there is 2 other ways.1. Use a inline converter and hook it up to the rear speaker connectors. this will convert the speaker's power to an RCA signal for the amp. On the fuse box, find the power remote- a +12V wire that turns on and off with the ignition. this will turn the amp on and off. this is the cheapest and can be done for as little as 25.00, but the sound quaility will not be very high as RCA signal is not very strong, and your using the factory radio EQ, which sucks. 2. you can use a JL Audio signal processor that hooks up to OEM equipment that provides a flat sound signal for amps, the remote wires, and aux inputs for ipods. This is the best quality option but very expensive.