20 Most Recent Pioneer DEH-1300 CD Player Questions & Answers

If your car has an OEM amplified system, make sure the blue (or blue/white if your radio has both) is connected to the blue or blue/white in the after market harness adapter.Also make sure none of the speaker lines are touching metal (grounding out) or touching each other

Google is your friend.http://smanuals.com/manuals/car-audio-systems/pioneer-autoelektronics/deh-5_15_1500.html

The yellow wire is your always-on power, so the clock and other settings are saved.Here's the manual.

COULD BE FAULTY BRAKE LIGHT SWITCH OR BULB SOCKET HAS A SHORT IF FUSE BLOWS ONLY WHEN YOU APPLY BRAKES.

The of the speakers is not important, but the impedance is. Check the impedance of the speakers using an ohmmeter and compare that to the spec for the head unit. Checking your maunal, which I found here: http://a248.e.akamai.net/pix.crutchfield.com/Manuals/130/1301300MP.PDF
your speakers should have a minimum of 4 ohms impedance. For more info, please read this post:
http://www.fixya.com/support/r9389300-stereo_says_protect_or_clicks_off_when

I suggest check in the next link the page 25... manual/95203_fr.pdf

Hope this helps (remember to rate and comment this answer).