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Old 13-03-2005   #1
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Guide: How to wire an Amp

This guide is how to wire an amp in the boot of your car. This method also transfers to different locations but obviously you will need run the wires a different way. PLEASE NOTE: I havent detailed how to mount the amp as this generally varies on amps and im trying to keep this as generic as possible. So here goes...

Firstly make sure you have everything you need to wire your amplifier to your car and headunit. You should need the following cables...
* Power OFC cable with Inline Fuse.
* Ground OFC cable
* RCA cable
* Remote wire
(sold in kits by autoleads, but you can also buy better quality cabling seperately)

You will also need the following...
* Crimp Terminals big enough to fit over the battery terminal and grounding point bolts
* Crimpers
* Soldering iron + solder (optional)
* Rubber gromet the same thickness as the power cable (optional)
* drill same thickness as power wire (optional)
* Rat tail file (optional)

Secondly, preperation can save alot of time, hassle and plasters from where you shred your hands to pieces laying cables So, take any trims off the side of the car (both sides) that lead to the boot. Also take the covers off that go under the dashboard. You will also likely have to remove or pull back alot of the carpet. Your basic aim is to have 2 clear routes from the front of the car to the boot to lay some cabling. If seats are in the way, its easier to take them out than to work round them You need two routes - 1 for the power wires (Power OFC and remote wire), and 1 for the RCA cable from the headunit (HU). Also, as you're playing with the electrics - disconnect your ground terminal of the battery before continuing with anything power related. You dont want to go blowing fuses left right and center.

Once thats sorted firstly you need to locate a place in the engine bay whereby you can run the power wire through the bulkhead easily but shortly. Avoid running the power cable too near to other power sources (especially the coil if can be avoided) as this can cause noise on the amp. If possible, try to use a rubber grommet that already exists and has non mechanical parts running through. Theres usually locations at the top corner of the bulkhead near the battery. If there is no suitable locations, you need to think about making a new one with the drill... When doing this, make sure theres nothing behind it in the bulkhead that can be damaged when drilling the hole through, and that its easy to run the wire through and get to from the inside... (if you do drill, also make sure to file any rough edges off the hole and use the rubber grommet for the hole. Otherwise you run the risk of shorting the power wire to the car body)

Once you've located a suitable hole or made one, you will need to start running the wire through. The best way that worked for me is to feed about a foot through the hole from the engine bay, then go into the car and pull the wire through routing it around various under dash components. You should just be able to poke the wire through as its quite rigid from its thickness. When you've got a clear place for the wire, just pull the rest of the remaining slack wire through. MAKE SURE YOU LEAVE ENOUGH WIRE TO CONNECT TO THE BATTERY AND ROUTE THE WIRE ALONG THE BODY!!!

Now you've run the power wire through from the battery. Its still not connected yet, but that can be done last. Now you need to run the wire from the front of the car to the rear. Try and keep it as straight as possible and away from moving parts - such as seat rails etc. You dont want to cut your power wire when you move things!! IF you prepared correctly, this shouldnt take long at all.

When the power wires there you will need to strip the end of the wire and crimp a suitable connector on the end. Fork terminals are usually the best for connecting to the amp. If you have a soldering iron, you may want to solder the wire to the crimped terminal too just for added protection. When the wires crimped at the amp end, screw it to the amp. You are looking for the +12v terminal on the amp...

Next you will need to locate a grounding point in the boot. Theres usually one behind one of the lights, or near there. Its basically a bolt with lots of other wires attached to it. When you find it, run the ground wire from it to your amp. The wire needs to be stripped at both ends with terminals crimped to it. One end (end to the body) will most likely need to have a bigger ring terminal so it can fit over the thread of the bolt, the other end is best having a fork terminal to connect to the amp. Again, you may benefit from soldering the terminals... When both ends are crimped with terminals, attach the ring end to the body (undo the grounding point bolt, add ring to the end and bolt back. MAKE SURE you dont leave off any of the other wires!!). Screw the other end of teh wire to the GRND (or similar) terminal on the amp.

You now have the power sorted at the amp end. You still need to sort the power wire at the battery end, but can be done last. Your next mission is to run the remote wire down the same route as the power wire from the headunit. Most headunits have a labelled wire saying remote. If not, then you will need to locate a powersource that only turns on when the headunit turns on. Failing that, tap into the continuous 12v power supply, and add a switch to the wire so you can turn off the amps manually. Just dont forget to switch it off otherwise your amp will stay turned on when you leave teh car or turn off the HU.

When you've located the right terminal (or made one ), you need to attach the remote wire to it. As both ends are most likely to be bare wire, either solder the 2 together and insulate with insulating tape or crimp some male and female spade connectors on. Next run the wire through to the amp down the same side as the power wire. At the amp end, screw the wire to the remote terminal. You may want to crimp a small fork connector to the end 1st.

You can now put back the trims on the side of the car that had the power wires running through.

You've not sorted most of the power. You now need to sort the signal side of things. At the HU end, on the back of teh HU there should be 2 RCA output ports. Plug 1 end of the RCA cable to this.

Now you need to run the RCA cable to the amp. Again shouldnt take long if you prepared correctly. Make sure that the cable avoids all powersources as possible as it would interfere with the quality of the amps signal. Garbage in surely means garbage out!! When the wires run through, plug the RCA into the input ports of the amp.

You can now also put back teh remaining trim and dash components as thats the last of the cable running.

Now you've come to the stage of connecting the power wire to the battery. For this you will need to ensure you have an inline fuse on the wire. Some wires come with them built in (from autoleads). If not then you need to connect one up. When done, take the fuse itself out and leave the connector.

Next you need to crimp a big enough terminal on the end of the wire that will go over the battery terminal bolt. If you bought a new battery terminal, there will most likely be a place to put the wire. If you're using the existing, an eyelet over the bolt should do the trick provided you bend it to shape..

Take off the +ve terminal, put the eyelet over the bolt and reconnected the terminal to the battery. (dont forget to do back up).

Thats sorted the Power side of things... Or has it? If you are running a pretty hefty amp, you may need to uprate the ground wire from the bodywork to the battery. Its usually quite thick as is, but may be worth considering upgrading...

Ok now you can reconnect the ground terminal of the battery. Leave the fuse out of the wire for now. At the amp end, wire in the speaker wires however you want your setup to work. (not covered due to many different configurations depending on amp use). Plug in the fuse in the power line. If it goes bang, cry But it shouldnt... If it does, you've got a short somewhere - probably where the wires run through teh bulkhead - check the wire for cracks in insulation.

Well thats it. You've connected up the amp correctly. Plug in your Headunit and see if it works!!! If it doesnt, the probable cause is either the remote wire isnt turning on the amp, or your RCA isnt feeding through a signal.

Happy Amping! Sorry for lack of pictures, i may add some at a later date when i get to take some. But i've tried to describe best so you can do without.
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Old 13-03-2005   #2
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Re: ICE 410 - How to wire an Amp.

If you have questions, post them here and will try to answer them when possible...

And if theres anything i've forgotten/ got wrong please point out. I wrote when slightly sleepy when i woke this morning! Should be fine tho
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Old 13-03-2005   #3
Ah. Not good...
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Re: ICE 410 - How to wire an Amp.

That's a pretty full account Luke!

There's one thing I'd like to point out though -

A lot of noise problems asscoiated with amps (whining sounds 'in tune' with engine revs) are due to improper grounding. Make sure that any paint that is around your grounding point is COMPLETELY REMOVED in order to maximise the grounding efficiency.

Also, and Luke has mentioned it, but I would like to stress that you must connect the power lead to the POSITIVE TERMINAL!!
I wired in a second hand amp that had no instructions and I accidently wired the amp to the Negative terminal. It took me a day to figure out why the amp wasn't powering up!
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Old 11-07-2005   #4
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Talking Re: ICE 410 - How to wire an Amp.

I've found that a lot of cars have perforations in the sound deadening/firewall that line up with a hole and rubber blanking plate under the bonnet.
This is really usefull as it saves removing lots of panels to get to the loom, which can cause interferance if u run the wire with them.

In the punto mk1 for example, if you pull the passengers carpet up there is an oval perforated in the deading. under the bonnet this is covered up with a rubber bung which has a small circle recessed into the back. To route the cable i cut the deading out, removed the bung and cut a small hole in it. This allows the cable to go through the bulkhead and exit under the passenger side carpet. It's miles away from any major power leads and can go straight into the cable clips under the door sills! You don't even know it's there!!
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