Adding Additional Fuse Box Focus MK2.5

[Solverz]

Hi Guys,

I would like to add an additional fuse box to my ford focus mk2.5 for extra high current accessories.

Can someone tell me or guide me in the right direction?

My initial thought was to have a wire connected to the battery then a fuse then the wire to go through the firewall and under the glove box. I then wanted to connec this to a relay which is switch by an igition live and then a wire going to the additional fuse box.

Would this be somthing that is okay to do or am I completely wrong ?

Any advice or reccomendations is welcomed!

I also understand that I can just use piggey back fuses but I think it will be neater with an extra fuse box.

[FatHead1979]

On 9/12/2019 at 7:13 PM, Solverz said:

Hi Guys,

I would like to add an additional fuse box to my ford focus mk2.5 for extra high current accessories.

Can someone tell me or guide me in the right direction?

My initial thought was to have a wire connected to the battery then a fuse then the wire to go through the firewall and under the glove box. I then wanted to connec this to a relay which is switch by an igition live and then a wire going to the additional fuse box.

Would this be somthing that is okay to do or am I completely wrong ?

Any advice or reccomendations is welcomed!

I also understand that I can just use piggey back fuses but I think it will be neater with an extra fuse box.

It seems like a LOT of work, in terms of the devices you're thinking of connecting up, what's the highest individual maximum Amp draw?

[Solverz]

On 9/18/2019 at 1:54 PM, 1979Damian said:

It seems like a LOT of work, in terms of the devices you're thinking of connecting up, what's the highest individual maximum Amp draw?

I'm happy to do it shouldn't take that long, and in total I'd like the fuse box to be able to take a maximum draw of 40amps

[Dee_82]

your going to be pulling 500w through this, what on earth you doing with it?

id use 4AWG wiring minimum if your keeping it under 20foot, if your hitting 25 foot then give yourself some margin and use 2AWG

Yes yes im sure people will say thats overly cautious but if it were my car, id rather be over the top then run hot cables which im sure the insurance company will question if your car goes up in flames

 

[Lenny]

I've been watching this thread without comment for a while now lol 

To best assist and advise you on the best way of spending your money; can you tell us exactly what your planning on fitting;

Is it an amplifier?  Two amplifiers?  

I've fitted two amplifiers; twin dash cam, tv tuner with pause & record, 10" roof monitor and a 1.0 fared capacitor, 

Some items need there own supply from the battery with a fuse or rather a trip switch within the first 12" inches, 

I've got two individual 4AWG feeds routed from battery to the boot for two separate amplifiers; one amp is on a custom built removable panel which unplugs for when the seats need folding down you then revert back to the headunits built in amplifier.

All connections are on sockets inside the rear of the panel just unplug from amp and plug Speakers in to a supply from the radio

No drilling or fixtures required; I designed it to sandwich tight between the seats with a 25mm cavity space inside for cables.

The red arrow below shows a socket containing four cables which are from the headunit front speaker output, unplug the feeds going to the front Speakers from the amp panel and plug in to the output from the headunit to continue listening while the panel is removed for folding down of the seats.

I would be sharing all this without reason; had you mentioned your plans at first I wouldn't be trying to cover possibilitys 😂

Myself and others can best advise when we know exactly what your planning. 

[Solverz]

@Lenny

I was looking at fitting an amplifier and thought why not just add an extra fuse box as it will make all other aftermarket wiring much neater along with other devices I have wired up.

@Dee_82

I am said 40amps to be better safe than sorry, I will definitely not be going near that

🙂

 

[Solverz]

 

This is what I was going for?

[Lenny]

1 hour ago, Solverz said:

@Lenny

I was looking at fitting an amplifier and thought why not just add an extra fuse box as it will make all other aftermarket wiring much neater along with other devices I have wired up.

@Dee_82

I am said 40amps to be better safe than sorry, I will definitely not be going near that

🙂

 

If your amplifier is 400w then a 40amp would be correct, 

I recommend fitting two separate power cables though,

keep the amplifier on it's own line with dedicated fuse as the pulse demands going through it would affect other devices if coming through a fuse board where the main source is being distributed.

If your amplifier is a class D then 8AWG is fine, if it's a class B or A then you will need 4AWG, if running two class D then you need 4AWG from battery to boot then splitter from one 4AWG down to two 8AWG outputs which then need to be fused independently to suit the requirements of the amplifiers 

A 25Amp cable then with a 20Amp fuse fitted within 12" of the battery would be sufficient for the small eh auxiliary fuse board, add smaller fuses then for each output device.

That's how I would do it; others may have there own opinion which I'm also interested to read too.

[Solverz]

35 minutes ago, Lenny said:

If your amplifier is 400w then a 40amp would be correct, 

I recommend fitting two separate power cables though,

keep the amplifier on it's own line with dedicated fuse as the pulse demands going through it would affect other devices if coming through a fuse board where the main source is being distributed.

If your amplifier is a class D then 8AWG is fine, if it's a class B or A then you will need 4AWG, if running two class D then you need 4AWG from battery to boot then splitter from one 4AWG down to two 8AWG outputs which then need to be fused independently to suit the requirements of the amplifiers 

A 25Amp cable then with a 20Amp fuse fitted within 12" of the battery would be sufficient for the small eh auxiliary fuse board, add smaller fuses then for each output device.

That's how I would do it; others may have there own opinion which I'm also interested to read too.

Awesome, putting it that way, it sounds better to have the amplifier on a separate line.

 

As for the aditional fuse board I want that to come live with the ignition so I was going to put a relay before the additional fuse board as seen in the image, now do you think it will be okay to put this relay behind the glove box right before the new additional fuse board as that is where I would fit it ? From my understanding this should be fine but would love to hear your thoughts?

 

Also when running the cable through the firewall, do you think it would be okay to run it through the grommet hole already there or should I make another hole in the grommet? Or does it not matter and I am over complicating it lol 😂

[Lenny]

2 hours ago, Solverz said:

Awesome, putting it that way, it sounds better to have the amplifier on a separate line.

 

As for the aditional fuse board I want that to come live with the ignition so I was going to put a relay before the additional fuse board as seen in the image, now do you think it will be okay to put this relay behind the glove box right before the new additional fuse board as that is where I would fit it ? From my understanding this should be fine but would love to hear your thoughts?

 

Also when running the cable through the firewall, do you think it would be okay to run it through the grommet hole already there or should I make another hole in the grommet? Or does it not matter and I am over complicating it lol 😂

The amplifier cable is very thick, especially the 4AWG I drilled a hole in the existing firewall grommet close to the original loom then taped the 4AWG to the original loom using PVC tape to unify the cone shape in to one sealed shape.

Then the new fuse board; you could get a piggy back fuse adapter then plug it in to the ignition live fuse for the 12v socket which is also 20 or 25AMP or the heated windscreen fuses there also 25Amp and ignition live.

This would save you both time and money fitting a relay unit; also providing you with the same amp output to put in to your new distribution fuse board,

just always ensure the amperage of cable your fitting is always greater than the amperage of fuse. For example 25amp cable with 20amp fuse is nice and safe. 

15amp cable with 10amp fuse also very good, 

Just to Note also: If your driving lights ever start flashing to the beat of the music then you can easily fit a capacitor in the boot as I have done myself to cushion or buff the demands from the battery typically a 1.0 Fared capacitor is good for up to a 1000watt amplifier, 

The best way I can explain a capacitor is to imagine you have a garden hose and your filling a bucket; the hose is consistent but takes two minutes to fill your bucket, 

When the bucket is full; you carry it to the Destination which takes another two minutes, the flow is a consistent level but the volume is limited.

Now that's a standard setup without capacitor.

Imagine now you have a large 200L open top drum; put the same hose in to that drum and yes its filling at the same consistent rate as your bucket did, 

However; when the drum is full; you can instantly dip in to fill your bucket to full capacity at any time you demand to a much higher volume, you dont need to wait and theres no lag, 

A capacitor is a reservoir of power feeding your amplifier; meaning your lights and other accessories wont fade when the base drops on your subs at 01:18 on Coldplay's track sky full of stars, 😅 at full volume or at 01:48 on Avicii Hey Brother, because the capacitor is there to cushion the demands.

I can also show you how to tune your amp for best output too, you just need a syn wave CD from eBay and a multimeter 

[Dee_82]

What Lenny said! (Good to see you again Lenny!)

One thing I may have looked over is the grounding. Grounding can cause all sorts of problems if its not right.

[Solverz]

@Lenny

Awesome, the explanation about a capacitor helped alot. Also once I have it all set up I would very much appreciate the tuning help!!

Regarding the new fuse board, I thought about connecting it  using a piggey back fuse but I would personally prefer to connect it to the battery with a relay, from what I have explained previously do you think it would be okay to do so? (taking into account all the ratings are correct, fuse etc)
 

Also all your guides are amazing, very helpful and I've referred to them alot with other small projects I have done😊

 

@Dee_82

I found that out the hard way when I fitted a new dab aerial which didn't ground properly 😅got it sorted in the end though 🙂

 

 

 

 

[Lenny]

14 minutes ago, Dee_82 said:

What Lenny said! (Good to see you again Lenny!)

One thing I may have looked over is the grounding. Grounding can cause all sorts of problems if its not right.

Hi Darren mate 👍

Earth feeds should be short as possible; 

I've earthed my amps to the upper rear seat bolts and inside the boot arch there was an M6 bolt hole 

 

[Lenny]

1 minute ago, Solverz said:

@Lenny

Awesome, the explanation about a capacitor helped alot. Also once I have it all set up I would very much appreciate the tuning help!!

Regarding the new fuse board, I thought about connecting it  using a piggey back fuse but I would personally prefer to connect it to the battery with a relay, from what I have explained previously do you think it would be okay to do so? (taking into account all the ratings are correct, fuse etc)
 

Also all your guides are amazing, very helpful and I've referred to them alot with other small projects I have done😊

 

@Dee_82

I found that out the hard way when I fitted a new dab aerial which didn't ground properly 😅got it sorted in the end though 🙂

 

 

 

 

Thanks mate, 

And sure no problem with all your planning; if you want to fit a dedicated relay theres no problem with doing that just keep a fuse on every line from the battery within the first 12" or 18" inches of line, 

Im working throughout the night so ill post a link in this post here later, linking to the details of when I tuned my amplifiers,

for you to view at a later date too: the cd is available on eBay very cheap, disconnect all Speakers, level all equalizer to flat, 

Play the certain track at medium volume 

Then plug multi meter in to the amplifier speaker outputs 

Followed by gently adjusting the amplifier gains screw up or down to achieve the correct ohm output, alot of people assume up full on the gains is best but its really creating distortion which reduces the performance more than anything. 

Anyways I'm going to try sleep now; I'll add link later 👍

[Lenny]

This video also explains the process 

 

[Lenny]

Heres a link to my build thread back when I was tuning the amps in my focus, 

 Thanks.

[Solverz]

1 hour ago, Lenny said:

Heres a link to my build thread back when I was tuning the amps in my focus, 

 Thanks.

Awesome, thanks Lenny I appreciate the help!