Right so there wasn't really a condensed forum post of how to fit an amp and sub to a MK3 Leon ST that wasn't the seat sound one, so I thought I'd post about the one I've just put in..
Firstly, getting the power wire through. Take the battery out and look towards the right hand side under the scuttle panel behind what I think are brake pipes and you'll feel/see a big ish rubber grommet which is where the main loom goes into the cabin. Pull/peel this rubber grommet down or poke a hole in it at your own risk. Then in the car under the glove box take out the little kick panel which is approx 3x T20 screws and a plastic finger screw at the back. Once you take that off you'll see where the loom comes through the bulkhead just push your power wire through there. I got 4 gauge through with no issues.
Once you've ran your power wire, use standard vag radio keys to remove the cd player from the glove box so you can fit your high-low inline converter for RCA's to your amp. After removing the cd player/ media box you'll see the big block black connector on the back unclip this and remove it from the box so you can tap into a door channel(s) of your choice. Personally I used the rear channels.
Looking at the diagram - the ones in the red circles are the tweeters on the connection block, to the right is the speaker channels. After you've tapped into the correct channels of choice you can plug it all back together and push the cd player back in. There should be a gap where you can dangle the RCA cables passed the fuse box and behind the trim where the bonnet pull is.
In terms of the 12V remote wire, Fuse 40 (20A) for the 12V is an ignition live so I used a mini blade fuse tap in wire to use that to turn the amp on and off. The fuse box is easily accessible by just pushing in the sides of the glove box and dropping it off its rollers/ sliders.
Towards the rear of the car there isn't any spare bolts/threads in the spare wheel well for the earth so I took off one of the plastic screws holding the boot trim (the internal cubby hole/ carpet covering plastic) in. Cleaned the paint off for a good earth and then placed the trim back over after securing the earth for the amp with a good connection.
Aaaand that's about it. My 12" type r bumps quite happy in my ST now
p.s taking the battery off and putting it back on will throw loads of driver assist errors on your dash. Don't worry most go away within a few meters of driving. Cruise Control and Stop/Start take a bit longer just take your car for a drive (enjoy your sick bad boy subwoofer) and then leave it for a bit when you come back after an hour or so they should be gone and working again.
Firstly, getting the power wire through. Take the battery out and look towards the right hand side under the scuttle panel behind what I think are brake pipes and you'll feel/see a big ish rubber grommet which is where the main loom goes into the cabin. Pull/peel this rubber grommet down or poke a hole in it at your own risk. Then in the car under the glove box take out the little kick panel which is approx 3x T20 screws and a plastic finger screw at the back. Once you take that off you'll see where the loom comes through the bulkhead just push your power wire through there. I got 4 gauge through with no issues.
Once you've ran your power wire, use standard vag radio keys to remove the cd player from the glove box so you can fit your high-low inline converter for RCA's to your amp. After removing the cd player/ media box you'll see the big block black connector on the back unclip this and remove it from the box so you can tap into a door channel(s) of your choice. Personally I used the rear channels.
Looking at the diagram - the ones in the red circles are the tweeters on the connection block, to the right is the speaker channels. After you've tapped into the correct channels of choice you can plug it all back together and push the cd player back in. There should be a gap where you can dangle the RCA cables passed the fuse box and behind the trim where the bonnet pull is.
In terms of the 12V remote wire, Fuse 40 (20A) for the 12V is an ignition live so I used a mini blade fuse tap in wire to use that to turn the amp on and off. The fuse box is easily accessible by just pushing in the sides of the glove box and dropping it off its rollers/ sliders.
Towards the rear of the car there isn't any spare bolts/threads in the spare wheel well for the earth so I took off one of the plastic screws holding the boot trim (the internal cubby hole/ carpet covering plastic) in. Cleaned the paint off for a good earth and then placed the trim back over after securing the earth for the amp with a good connection.
Aaaand that's about it. My 12" type r bumps quite happy in my ST now
p.s taking the battery off and putting it back on will throw loads of driver assist errors on your dash. Don't worry most go away within a few meters of driving. Cruise Control and Stop/Start take a bit longer just take your car for a drive (enjoy your sick bad boy subwoofer) and then leave it for a bit when you come back after an hour or so they should be gone and working again.
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as in all previous cars ground is attached to the seat belt buckles bolts under rear seats. Never had any connection problems using that area for ground connection
