Does the pioneer DEH-3400 have a subwoofer port?

SOURCE: wiring diagram pioneer deh-3400

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ihave this for you

SOURCE: Connecting Pioneer DEH-2000MP to an amplifier

Hi and welcome to FixYa,

You would need a special adapter that connects to the speaker wires of the Pioneer DEH-2000MP and converts them to line level RCA ports. Something like the image below and available from here or most car stereo stores.

Good luck and thank you for using FixYa.

SOURCE: aux port

Turn off Radio with car on or key on. Press and hold the big volume button in for 3 seconds, and the radio will say initialise. Than press the FCN button till it says AUX. Than press the SEL button till it says "Aux ON ". Turn on radio and you should be good to go.

SOURCE: Can't fit subwoofer amp leads to pioneer DEH-2000MP Head unit

pioneer head units only distribute like 200 rms or so to the speakers. you might have to find a blue maybe even blue with white striped wire and nick it just enough to tie your amp wire around it. tape it up and see if it works.

SOURCE: car stero wiring diagram

Here you go