Originally Posted by EAtDUST
For the relocation (due to turbo) i'm thinking of connecting the distibution block to the fusible links/starter power (all positive wires) in the engine bay and running them to my inline fuse on the firewall. The 2gauge would run from the block , to the fuse , through the firewall , under carpet , to another inline fuse in the boot and then to the battery box..................................
1) What rated fuses should i have in each holder (boot and engine bay)?
2) Is the cable strong enough?
Whenever you run cable of any sort, there are a few things to consider.
1st: The maximum load to be carried by the cable in amps.
2nd: The length run of the cable.
You might have 200amp cable, but this value(amps) will be less the further your length of cable is. If it's automotive cable (200amps), I would think that this would be for no more than say 2 meters of length. So, if your length from engine bay to boot is say 5 meters, this cable then de-rates it's permissible load by say about 50amps continuous. The cable will now only be rated at say 150amps.
In my view, a good indication to see if your cable is big enough (for its total length & load), is to load it to your desired amps(max), and see if the cable begins to get hot. If it does so within say under 30 sec, the cable is not big enough. The hotter the cable gets, the more it begins to draw in amps, even with the same load applied.
The one in your boot, is to protect the cable over it length run.
This size fuse can't
be greater than the rated amps of the cable....installed. If you take the above explanation, and your cable is calculated to be 150amps, your fuse should not be larger than 150amps.
The in-line fuse under your bonnet is to protect all your accessories running from the distribution block. This should always be smaller than the above fuse, but about your max Amps to be drawn.
Head lights/driving lights 20A
Stereo with amps 70A
Heater on 10A
General accessories 10A
So this fuse will be around 110Amps, BUT NO GREATER THAN 150A.
If this calculated load exceeds 150amps as in the above example, you need larger cable.
You will find the largest load will be the starter motor, but you shouldn't have your stereo blasting at the time of starting your engine, otherwise, you will need more than a 200amp rated cable I would think.
Hope I have been clear enough.