Roosie

iTrader: (8)

i know its a bit pony but you get the idea.


does this look ok?

i havent done the wire thickness yet but does the rest look ok?

StephenC

not sure about 30a fuse for starter solenoid or the need to use a relay? thought a low current pulse to the solenoid then big starter cable taking all the big current. everything else looks alreet to me though.

stu21t

yea as above, no fuse/relay needed on a starter
and for the fan, i would also run a switch live from the std fan switch as well as a toggle to the relay to trigger it.
and make the trigger for fuel pump and fan come from an ign live not battery, otherwise they could over run and if u forget to turn em off, drain the battery.

Roosie

iTrader: (8)

thanks guys but im using a isolator switch so thats as good as ignition as it will be switched off after use. cheers

stevieturbo

Correct, no fuse for the solenoid, but not for that reason.

I'd say there is a good chance a 30A fuse would blow. The current required to pull in the solenoid is quite hefty which is why most starter circuits dont use a fuse.

StephenC

you sure you understand the principle??
http://en.wikipedia.org/wiki/Starter_solenoid
30A through a wire that small??!!

jon@work

iTrader: (5)

I presume you want to use a relay on the starter solenoid circuit because of the switch rating ?

If you replace the on/off switch with a on/on switch, you could also keep the standard radiator switch to operate the fans if you don't want to keep an eye on your temp gauge as well as having the manual overide functionality.

It's worthwhile fusing the low current wires in case of wire damage etc.

StephenC

^ I'd go with that, all bases covered and nice and safe

Roosie

iTrader: (8)

actually on the fan its ecu operated so were does the wire from ecu goto on the relay.

cheers

Roosie

iTrader: (8)

my starter button its rated at 25amp also.

cheers

Christian and Beccy

iTrader: (14)

You'll need a bigger fuse on the fan circuit, with blades like that it will be under increased load.

stevieturbo

I understand perfectly. If you check, most solenoids have either a large spade terminal, or a bolted on terminal. And usually relatively heavy gauge wire. Also dont forget that it isnt a slow draw of current, its quite a large one albeit over a short duration of time. ( although on some Fords...that could be a longer period :P )

SO wire gauge may not always be as heavy as might be needed for a sustained heavy load.

Either way, the solenoid does draw a fair bit of current and could blow a fuse quite easily, unless perhaps a slow blow fuse was used.

stevieturbo

The ecu will normally provide a ground to energise any relays.

So you'll normally either provide it with a permanent 12v, or ignition based 12v on the coil side, and the ecu trigger on the other ( ie ground )

Roosie

iTrader: (8)

so would i still need a relay or is it just a case of wiring the ground wire from my fan straight to ecu wire?

tabetha

Keep the fuses as near the battery as you can, as said the k3 will control the fans, though you can have amanual overide if you want, last thing you want to be doing when racing is watching a guage for temp, let the ecu do the work, set at what temps you want.
Most wire will be ok with 16/020(thinwall) which carries 11 amps continuous, or next one 32/020 carries 16.5 amps continuous, solenoids as said do take a whack of current to move but much less to keep it there, so wouldn't bother with fuse either.
I've got 200 metres of black and red 16/020, and 32/020 as well as 28/030(25amps)
tabetha

tabetha

YES you still need a relay, as otherwise will damage ecu, the ecu merely switches the relay like a switch does.
tabetha

Roosie

iTrader: (8)

well the battery is behind passenger seat and fusebox and relay box is behined the dash.
Ive got 30m of 2.5mm2 29.0 Amps
and 30m of 0.5mm2 11 Amp 16/0.20

stevieturbo

Dont forget. Everything doesnt need wired back to the battery as shown. Although it will need wired to a suitable 12v feed.

That can be at the battery, the starter, the alternator, or another chosen connection point that you create.

Items like coils, fuel pumps etc are sometimes better wired directly to the alternator, as that will be the main power source for everything when the engine is running.

Or if not directly to the alternator, directy to a connection point which has heavy gauge wire from the alternator.

I have a fusebox/loom/relay panel wired directly off the alternator via 16mm^2 welding cable, which in turn goes directly to the starter motor, which then has 35mm^2 welding cable to the battery at the rear. My fuel pumps are fed directly off this.

So in essence, whilst there is some length to it, the cable feeding my pumps is no less than 16mm^2 from the main power source ( alternator ) right up until it has to step down to accomodate fuses and relays.

Welding cable is ideal too as its very flexible, and has quite thick insulation. ALthough obvioiusly its only to provide suitable power takeoffs

tabetha

Certainly got enough between us, you shrinking it and all that ?, I've got around 40 metres of 3/4"(4-1 ratio) in black, but have some pink also!!
Just bought me bubble gum pink paint for the 6 pots today!!
tabetha

Roosie

iTrader: (8)

im going to run a junction box behined the dash from the battery. yeah i want to shrink most of it to make it look a lot better.
surely if running of alternator if your belt snaps thats it all power down. but anywere else will run off battetry?

StephenC

your alternator will be linked to battery to charge it so everything else will still run, you'll just start to loose power gradually.