Car Stereos: bypassing factory amps in 02 jeep liberty, factory amps, passive crossovers

Question
hey brian, you seem to get asked this a lot and i tried to find the answer in previous posts before wasting your time but couldn't, so if i missed it sorry. i just need help bypassing the factory amps in my wifes 02 jeep liberty. any help would be great.

thanks, nic

Answer
Hi Nic,

Bypassing the factory amplifiers should only be done if you're upgrading the stock speakers with after-market replacements.  If you're just replacing the head unit, then bypassing the amplifiers isn't necessary or recommended.

The stock amps are mounted directly to the front door speakers on each side.  Each amplifier has a 10-pin plug with the following wires:
-12V power
-ground
-front channel inputs (+ and -)
-rear channel inputs  (+ and -)
-dash speaker outputs  (+ and -)
-rear door speaker outputs (+ and -)

In addition to the 10-pin plug, there will be two wires from the amplifier to the terminals of the speaker on which the amp is mounted.

When you bypass the amp, you'll be doing two things:  connecting the front channel input wires directly to the new front door speaker, and connecting the rear channel inputs directly to the rear door speaker outputs.  Once this is done, the front and rear speakers will be connected directly to the head unit's outputs.  The dash speakers will be disconnected.  If you have a good full-range door speaker, you probably won't miss the dash speakers; but if you want to keep them working you'll need to purchase passive crossovers for them.

Here's the procedure:

1.  Remove the front door speaker and unplug the amplifier.
2.  Connect the rear input wires to the rear speaker output wires.  In the driver's door, connect the brown/yellow wire to the white/red wire, and connect the brown/light blue wire to the white/black.  In the passenger door, the colors are dark blue/white to tan/violet, and dark blue/orange to tan/black.  It's up to you how you connect the wires; I prefer to strip each wire without cutting it, and solder in a jumper wire to connect the two factory wires.  The advantage to this is that later you can cut and insulate the jumpers, and plug in the factory amp again if you wish to return the vehicle to stock condition.  If you don't plan to put the stock amps back in, then you can just cut the wires and splice them together.
3.  Extend the front input wires and connect them to the new front door speaker terminals.  In the driver's door, the front wires are dark green (+) and brown/red (-).  In the passenger door, the wires are violet (+) and dark blue/red (-).  

Hope this helps!

Brian