if you've got a relay with a fuse in it, does this mean you dont have to bother putting a fuse in the +ve feed

and if the circuit normally has a 20amp fuse in it, does this mean im gonna want to use a 20amp relay? will using a 30/40amp relay still be fine (and can i use a 20amp fuse in a 30amp relay)

cheers

oh, one more thing if i'm feeding the switch part of the relay from a physical switch, do i just wire the switch so that it has +12v on one end, and the other end goes to the relay activator thing... i dont earth the switch or anything stupid do it.

ps i know the above are really stupid questions, but if assumption is the mother of all fuckups and i dont want to assume that i know what the hell i'm talking about

 

You can always use lesser fuses in heavy relays, no problem.

Don't put in a bigger fuse though, you might burn out the relay then if you use higher currents.

 

Best is to use a fused +12V feed to the relay activator thingie , then use the switch on the earth of the relay. Less change to fuck it up, worst thing is when you short the switch it will keep the relay activated.

 

danke schön

 

when you say use the switch on the earth of the relay, do you mean connect the relay so that it switches the +0v instead of the +12v as its safer?

if so thats impossible for me as i need a relay on the live side AND the earth side (as i have two seperate switches used to activate the circuit!)

 

I think the relay fuses the main heavy load circuit only, so no u wouldnt need to fuse that circuit.

yes the relay needs to be able to cope with the heavy load circuit, so it needs to at least match the fuse u would be using, u could use a 20amp fuse in a 30 amp relay, but not the otherway round.

Thats correct, unless the switch has a light or LED to indicate its staus, then u will need to earth the switch too to make it light.

 

Where are you putting the relay? I take it you are connecting the main big feed from the battery?

If the relay is close to the battery, then no other fuse required. If the relay is, say, inside the car then you could have a problem as the bit of cable from batt to relay is unprotected. If it rubs through somewhere (bulkhead for instance) then you will have a fire.

 

relay will be mounter nearish battery (ie in engine bay)

and yes im taking the feed straight from the battery

incase you're curios as to what i'm upto, this is the wiring for the nitrous pulsoids, if they do not receive a good, clean feed then they do not fire properly. in order to do this i currently have the arming switch mounted in the engine bay! this is obviously no good as i want it in the dash, so i wanna wire them in via relay and have the arming switch on the dash arm the relay.

also the relay on the -ve side is for the throttle switch, normally you just run the switch in-line to the earth (so its a switched earth that fires the pulsoids) but i am using the automatic kickdown switch on the car to arm mine (which works REALLY WELL!) and i do not trust that this can give a clean enough earth (current etc) when wired up directly as a switch, so i want to wire up this switch to ativate another relay (so when the switch goes live it will make the relay activate and earth out properly, completing the circuit and making the pulsoids activate)

 

just to check something on the relays...

i want pins 1 and 2 to the battery and to the solenoids (the things to be fed)

3 i dont wire up (or do i earth it?)

and 4 is from the switch

is that right?

please excuse the shit drawing...

 

Jim,

Use the proper numbers on the relay man!

Basically, it depends on whether your switch is on the earth side (preferable) and how you want them wired up.

 

rich, relay's in the box in the car n i cant remember numbers off top of me head (might go grab it in a minute tho)

i have 2 relays...

one's on the live side, one's on the earth side

 

1=86 2=85 3=87 4=30


heeelp, i cant work out what goes where

i have 3 connectors

1 input from batt
2 output to solenoid
3 switch

what do i connect each one too

 

dont worry, sorted now, i found a diagram via google

nitrous all works pukka now, looks cool too nice n tidy (unlike it was... lol)

 

nice!

your car is the mutz nutz!

 

thats fucking disgraceful. How long before this one goes up in flames?

please tell me you're not leaving it in that state?

 

whats disgraceful? i'm open to constrictive criticism, i really am?

if youre worried about waterproofing etc. of wires its all in hand, but as for anything else, i cant think of anything iv done thats "naff"/dangerous?

or do you mean the huge collection of wires that were already there?

 

Jim,

For a start, I would have used insulated spade terminals.

Why use open ones, when covered ones are more readily available?

As force of habit, I always heatshrink over every single terminal too.

I presume you're not so pikey as to leave the relays dangling?

 

relays are screwed down.

as for covered terminals, good point, easier than wrapping them up i s'pose! i've got some aswell, i'll swap em tomorrow

heatshrink i've got aswell so cant hurt to use it...

keep em coming, i really do want people to pick holes, as i want it to get it spot on...

 

I'm just going off what I can see in the pictures here but...

the relays look 'thrown under the bonnet' - why aren't they next to each other, screwed down and aligned perfectly?

then the red and black wires that go past the cone filter would be the same length and could be taped up to form their own loom.

same goes for all the wires that run from the battery area - they could all be the same length and taped up in their own loom.

The earth wire linking the two relays would also be much shorter and neater.

also the wires to the nos solenoids look like they are joined with crimp terminals - they'd be better soldered if at all possible.

and as said definitely use insulated terminals - if a relay moves or a wire comes astray you could have big problems! (although I assume its all correctly fused?)

if done properly and neatly you would only see two relays (perfectly mounted next to each other), one loom going to them and one going to the solenoids, all taped up and neatly fastened out the way.

seen as you are doing it yourself and not paying for labour charges you may as well spend as long as it takes to get it perfect!

and sort out the rest of the wiring 'nest' by the battery while you are at it!!

 

thanks henry, all good sugestions

just to let you know tho (just so i dont look lik a complete numpty)

relays are there becasue there were already 2 perfect size holes and i didnt have a drill handy to make any new neat ones... i'm gonna move these to the wing

the wires are not perfect lenght becasue im still not 100% sure of the final relay location

earth wire is big coz i cut it too big n couldnt be arsed to re-crimp a shorter bit

the nos solenoids ARE crimped, this is the connections they supply in the kit, i dont wanna solder them till im 100% happy with the mounting locations

as for insulated trminals, thats me just not thinking straight, i'll swap em when my hands recover (theyre sore from crimping shit all evening )

as for that nest... i aint fuckin touching it, its too complicated

 

I can't quite see from the pics, but get yourself some ratchet crimpers Jim, as you get a much better connection using them.

 

You can buy nice relay connectors, much safer then using spade connectors.



Or if you mount them on a PCB and put them in a box.



Then you will be sure no connections come loose. As spade connectors are crap with relays, you end up getting bent pins etc... (I do anyway)
Much easier to do it neatly with the above connectors.

 

And it looks like you use a eath feed from the battery ?
Better take the same earthing point as the front light, then tape it up with the 2 wires going to the solenoids back to the relays.

That will at least get the "nest" at the battery easier.

 

that looks ace joris, where can i get some, maplins maybe?

and rich, what are rachet crimps?

to start with i was just using pliers (i dont own any crimpers) but later someone lent me some crimps to do the last few connections...


...i actually found it easier/better with the pliers tho

 

yes ive used an earth feed from the battery, i figured that way i can guarantee that itll get a good earth

 

Oh and for the earthing tip, start doing that with all crap that is connected to the negative side at the battery that ford didn't intend to be there. Look for a earthing point as close as possible to the device that needs it and take that away from the battery point.

As for the positive side of the battery, if you really need so many wires leaving from there, get a little 2nd fusebox. 1 wire going from battery to fuse box, and then you can safely distribute wires all over your car if you like, but at least it will look much better. And be easier to find the broken fuse if anything goes wrong.

 

top ideas

 

I get the connectors from velleman in Belgium, but I guess any electronics supplier will have them ? At velleman there under the category "heavy dute car relays"