85, 86, 30, 87 & 87a?

Why these numbers?
Now,i'm going to fit some work/spotlights to the back of the van,i've done my home work,read this and understood what each does and why
https://www.12voltplanet.co.uk/relay-guide.html
I'm going to follow this method in doing so
https://i.pinimg.com/736x/5f/0e/b7/5f0eb786e612fa50dd4e41395d751513--circuit-diagram-jeep-stuff.jpg
Now i have a relay with 5 pins with a built in 30amp fuse but my wires are different colours(if that didnt confuse me even more),i've done/copied me layout on paper and pretty sure i'm good to go
BUT
I have a question
Why those numbers,why not 1234/4a or 12345 or even still,letter them?
Just curious thats all

 

Pictures of the relay would help..

 

It's normally self explanatory with the circuit diagram.

 

https://en.m.wikipedia.org/wiki/DIN_72552


Really uninteresting reason

 

Help with what?
Those are the numbers on the back of it,like i said i've done my homework on what goes where just curious to know why pick those numbers,thats all

 

I'll get some photos at work tomorrow if you are still lost.

 

The numbers are part of a DIN standard for automotive wiring,

It does actually start at number 1..
https://en.m.wikipedia.org/wiki/DIN_72552

 

Wake up already posted that link. Hehe

 

thanks for that,now i see,but might be for you,as for someone whos not got a clue its usefull to know,lol

 

It's still useful to know with the modern stuff.
Random example but if you want to change the ECU coding for door mirror folding on a vw transporter the software gives you the option of choosing terminal 15 or not. Head scratching until you check that list and can see that 15 is controlled by the inigition switch.

 

Also, I would imagine your relay has the capability of switching a 30a load rather than having a 30a fuse built in, although I'm sure you could probably get such a device.

So you will still need to fuse the circuit, the size will depend on a number of things, but ultimately the item with the least current carrying capacity.

 

@xstian this is what i have

 

I said you could probably get such a device. My apologies, it looks like you are all all over this.

It's surprising the amount of people who think because something has a current rating written on the side, it must be fused.

 

Those relays with inbuild fuse holders should follow the same numbering system as all the others.

I dont like them as the fuse contacts seem to corrode easily but mount it in a dry location and it should be fine.
You might want to swap the fuse for a lower rating though (depending on the power of the lights) and wire it directly from the battery or an accessory circuit rather than piggyback from something important