2001 hyundai accent, alternator

another question i would like to ask is im going to do the big three ugrade before i get a higher amp alt and was wondering can i leave the factory fuse in the fuse box and just connect the new wires up to that or do i have to upgrade the fuse holder and then put a new fuse in with the same value? 

Feel free to correct me if i'm wrong guys, i'm still learning here!

Good lord take your damned capacitor off. Those things are actually harming your systems current draw. If you have any clue what they are used for then it's best to take your capacitor off. Yes it may be your alternator I would recommend getting at least a 150A alternator if not more.

ok thanks for all your comments but would also like to ask im going to upgrade the big three is it best to use 0AWG  cable or is it ok to use 4AWG as i think the 0AWG would be too thick to go onto the battery terminals without hitting the bonnet as the battery it so close as it is with the standard terminal connections.  and also another question at the moment if at a show and i turn my system up to over say 40 on the volume it blows the fuse.  now what i wanted to ask is that the setup is from the battery it has a 60amp fuse which then goes into a distribution box which the two amps are run from both fused again now my big amp is fused with a 125amp fuse and my smaller amp a 60amp fuse so as its blowing the 60amp fuse before the junction box does that mean that its too small and i shoul up it to say a 100amp fuse?  the power cable is 4AWG if that helps. 

You fuse is obviously too small for the load. Either upgrade it, or keep the volume low. The hotter a fuse gets, the closer it is to its rupture current. If wires get warm, they are probably too small. It is often impractical to run the desired cable through the entire system. Hence why junctions may be used. EG - a short fat cable runs from the battery + terminal to a nearby chassis-mounted juntion box - typically a fuse or circuit-breaker (since that is required and probably cannot be mounted on the battery). From there it can be whatever 0 or 00 guage(s) to the loads. Similarly at the other ends. And maybe for the battery grounds. The point is to minimise the lengths of undersized cable to minimise total resistance and hence voltage drop. And also make sure the thinner cables do not themselves become fusible-links - ie, protection should operate before the cables fuse (unless deliberately designed as a fuse point for multi-thousand Amp loads!) However, it should be the alternator that supplies the loads rather than the battery. Hence one of the reasons for dual batteries - ie, a second battery (typically AGM/VRLA) next to the amps (big loads). The second battery has the main heavy cabling for the system. Then just a reasonable sized cable is needed from the alternator to the second battery (ie, not from the first battery). (Noting that the alternator cable is rated for acceptable IR voltage drop at full output. When the alternator's output is exceeded, its voltage drop from (say) 14.4 to 12.6V way exceeds any IR drops. (Or should anyhow!)) BTW - t&t tech - excellent replies IMO! And you are so right - how can "Amperes" fry an ECU?? As to others wit their BIG sparks when shorting high current DC systems - welcome to the world of automotive batteries, and high-power 12V audio systems!

Yes as oldspark said your fuse is too small! Also a thing i learned on this site is you fuse according to the wire size and fuse again when a wire is downsized!commit your way to jehovah and he will act in your behalf. psalms 37:5

t&t had learned well. Fusing for wire size is the general rule. But there are exceptions. EG#1 - Physical Security As per my "short run" thin cable from the battery terminal to a fuse or heavier cable - the thin cable isn't fused (because (1) it may be rated at less than total demand & (2) we used it BECAUSE we couldn't run a thicker wire to the battery terminal &/or fuse it there). Noting also that a fuse positioned above a battery is not desirable lest it trigger a hydrogen explosion. This example may be considered instead to rely on "physical security" which is used where electrical protection isn't possible (eg - telephone exchange DC systems). It also assumes the thin cable's downstream terminating fuse will melt (rupture) BEFORE the thin cable does! EG#2 - Oversized cables relative to the load. Maybe a 4G wire with its 4G-fuse (say 120A) is adequate for our load. But we want a lower voltage drop so we use 000G wire (1/4 the resistance of 4G) for most of its run. Instead of a (say) 320A fuse at the start of the 000G, the 120A to match the load is ok. This reduces resistance since each fuse adds resistance, and we do not need the 320A for the 000G since its substituted 120A will provide the same protection for the 000G and the downstream 4G. The above example should be an obvious exception to NOT "fusing to suit the wire". Instead it is sized for the maximum load current (being less than the cable/wire rating). The fuse may approximate the load fuse sizing (but is usually bigger than a single-load's fuse) but should NOT be confused with (each) load(s) own protection fusing. Also bear in mind that wire ratings are based on some parameter - usually heating. But that may be far short of its rupture capacity - it may be to prevent insulation deterioration. (The only wire rating I use is resistance - I will typically design for a maximum allowable voltage drop.) Alas the all the above are simplified and hence their detail is incomplete. They are based an various practices but that vary with design intention. And they assume resistive protection. Magnetic & Hall etc circuit breakers may have negligible resistance and hence not as undesirable. (Except for the subject of "discrimination" - eg, ever seen a 200kVA UPS's protection operate before a 16A end breaker, hence dropping the entire 130kW of critical CPU load instead of just the faulty 80W monitor/2.4kW circuit? (aka "Professional Design".))