Hey guys, i just finished installing my amp in my MM. I have a JBL BP1200.1 which i needed to run 4awg wire to. Im a MECP certified installer, and was a bit nervous taking my car apart(mainly cause its mine!!!) But in the end, it came out flawless and the temporary sub i have sounds great. I will eventually put in my kicker comp vr 18" sub where the trunk organizer goes, once thats complete i will share pics!. But i will share some tips/tricks that i discovered.
Running the power wire thru the firewall: The most feared part of all! The space to run the wire is right below the "bicycle stlye" cable that goes under the hood. Its to the left, bottom of the factory computer. there is a spot to run any size wire needed. You first need to cut out a small section of the sound dampening material that mercury uses, on both the inside and outside locations. You will need to unplug the ECM and the other connection that is to the left of it. Its the same process as installing the chip! So if you've done this, you knbow exactly what im talking about. I used a specail self sealing grommet that once you tighten the "screw" over the wire, it makes a water proof seal. I remember some of you had water leaks from faulty installations, so i made sure this seal was done right!!
Running the wires on the drivers side of the car. The door sills are a pain in the a$$ to pop off, i did break of 2 of the plastic clips, but was able to glue them back on. You need to life strainght up and pull very firmly, or else its not coming off. DO NOT TUCK THE WIRES UNDER THE SILL. This looks like crap and makes buldges uner the sill. Once the sills are off. Take a 7 mm nut driver and remove the 2-3 screws holding the plastic housing for the factory wires. There is plenty of room to fit your aftermarket wires in there, this will ensure you have no buldges in the sill or in your carpet! Do the same for the rear drivers door area. And the same setup goes for the RCA's if you install them, just run them on the opposite side(passengers side) to avoid getting engine whine!
Remove the back seat per instrustions on replacing rear speakers: You will see there are plenty of spots to run the wires thru, you just need to find your location of your amp. I put mine directy under the factory sub. It takes up the least amount of space there! If you are running high level inputs to your amp, meaning no rca cables, on the right side of the sub you will see a black wire and a black wire with a white stripe. These are your signal wires, just use the white strip as (-) and black for (+) and connect them into your amp. This way your using a sub signal, which is already crossed over for you! This avoids blowing up your new subs!
Now for the ground, just use the bolt that holds your rear seat backing, this will provide you with the best ground. Next power it all up and enjoy your new audio system!!
Frank