relays ?

[retromadness123]

Hello guys, I'm trying to get my head around relays so need some help, I see a 30amp relay has 30,85,86,87, and some include 87a, also I seen other replays with 3 pins and some with 5 and 4, with different numbers like a 5 pin - 53e,53c, 31b,31,15, or 3 pin- 31b,30,15,I want to know what these numbers all mean, and what would happen if a different relay was used, also I will be using a 30amp 4 pin for my upgraded headlights, 30,85,86,87 but could i use the 5 pin 53e,53c,31b,31,15, I'm just trying to get some knowledge how all.these numbers work and what they mean, thanks all help appreciated

[Anthony]

The basic 4 pin relay is quite simple.

85 and 86 forms the low current switching side of the circuit

30 and 87 forms the high current switched side of the circuit

87a on a 5 pin relay forms a circuit with pin 30 when the relay is not energised and that circuit is broken when the relay is energised (and a circuit formed between 30 and 87 instead)

For a headlight application, you would wire a standard 4 pin relay as follows:

86 - connected to existing headlight wiring to act as the switching circuit
85 - connected to earth
30 - fused direct connection to the battery positive (or similar)
87 - to the headlight

If using a 5 pin relay, leave 87a disconnected for your application.

Hope that helps

[retromadness123]

Thanks Antony, that's does help, but can I still ask why there's different numbers on different relays just a matter of interest thanks again top man

[optimusprime]

Link.

Hope this helps.

[retromadness123]

Thanks I will have a look at that link, also I been on a site which shows how to upgrade the headlights the earth wire for the 85 pin goes to the negative terminal would this be ok or would I need to put it on to the body, thanks

[duggers]

This is an article on relaying VW headlights but the principle is identical. Gives a good explanation on relays

www.timbox.net/technotes/category/lighting/

[retromadness123]

Thanks duggers, really appreciate that,the car in question is a mk1 golf so this will help loads, I was on google and came across a different post for a mk2 golf and it just showed how to do the low beam, so I have already ordered bits I need for that but I see it wont be much more of I want to connect my spot lights and high beam bit first would like to do the basic lol as I'm a bit nervous, hope it goes well and thanks again guys do appreciate all the help,

[outrage]

DIN numbers explained:
vintagebus.com/wiring/defs.html

53e,53c, 31b,31,15 for example is a wiper relay and is not of much use here.