mrazntre
12-29-2003, 09:09 PM
I've always been bad at remembering the pole numbers and the inner workings of relays, but I know the basics that the low current power is transformed into higher current power when the relay is activated...errr something like that. Normal switches can't handle the amount of power that it takes to power up something like fog lights, it'll just burn out (although you can use higher amp rated switches, but that's usually not the case).
Anyhow.. I'll be brief, there are a whole bunch of relays, but most commonly you'll see either a 4 or 5 pin relay (most popular brand is Bosch, but there are others). The 4 pin has one function, if the relay is activated, something is turned on. The 5 pin has two functions (or modes I guess), if the 5 pin relay doesn't see power across pins 86 and 85, it'll do one thing, but if it does see a current between the two, it'll do another thing.
I can't even explain this properly, but let's keep going. Since I have a 5 pin in front of me, I'll go with the 5 pin ( the 5 pin can do what a 4 pin, but not vice versa. when using the 5 pin as a 4 pin, you'll have a leftover pin).
The relay basically looks something like this:
stupid--
shit| -- |
stupid|
The very top two dashes are the 87 pin (this basically sends the power signal to whatever you need to be powering, ie. fog lights).
The next line, the vertical is the 86 pin (this is used in conjunction with the 85 pin, the next vertical line, to power up the relay). These two pins are basically interchangeable between the ground and the signal that is received from the switch, which has power. But for all intents and purposes, the 86 pin will be the ground (-).
The next two dashes are used when the relay is in dual mode, or when it's actually being used as a 5 pin relay. For now, this will be empty. BTW, this is the 87a pin.
The next vertical line is what we've discussed, it's the 85 pin. This will receive the (+) signal from the switch, which will activate the relay.
so now we have the third vertical line which is pin 30. This is the pin that will receive battery power (+) (from the battery directly or some other power source, sometimes ACC power (Accessory power, you know the stuff that only works when you move the key one position, such as your radio, headlights, etc.)
So basically once there is a current that passes from 86 to 85, the relay will "click" and channel the power that is going from the 30 pin into the 87 pin, which will then light up the foglights or whatever accessory you're trying to power up.
As with the middle pin, the 87a, if you were going to use the 5 pin as a 5 pin, then you'd just hook that up to something that you want to be running all the time. This would be in the case of a sidemarker light that lights up with the parking lights, but then also flashes when you signal. The "parking light" mode will be 1 function, and the flashing mode will be another function. This is why you use pin 87a (and that's why it's 87 and 87a, because basically they do the same thing, but at different times). or something like that.
*note* you can wire up a relay to work either 1)switched ground or 2)switched power.
If I don't make sense, it's normal because I get confused about this shit sometimes. Perhaps I'll draw a diagram one of these days.
edited
Anyhow.. I'll be brief, there are a whole bunch of relays, but most commonly you'll see either a 4 or 5 pin relay (most popular brand is Bosch, but there are others). The 4 pin has one function, if the relay is activated, something is turned on. The 5 pin has two functions (or modes I guess), if the 5 pin relay doesn't see power across pins 86 and 85, it'll do one thing, but if it does see a current between the two, it'll do another thing.
I can't even explain this properly, but let's keep going. Since I have a 5 pin in front of me, I'll go with the 5 pin ( the 5 pin can do what a 4 pin, but not vice versa. when using the 5 pin as a 4 pin, you'll have a leftover pin).
The relay basically looks something like this:
stupid--
shit| -- |
stupid|
The very top two dashes are the 87 pin (this basically sends the power signal to whatever you need to be powering, ie. fog lights).
The next line, the vertical is the 86 pin (this is used in conjunction with the 85 pin, the next vertical line, to power up the relay). These two pins are basically interchangeable between the ground and the signal that is received from the switch, which has power. But for all intents and purposes, the 86 pin will be the ground (-).
The next two dashes are used when the relay is in dual mode, or when it's actually being used as a 5 pin relay. For now, this will be empty. BTW, this is the 87a pin.
The next vertical line is what we've discussed, it's the 85 pin. This will receive the (+) signal from the switch, which will activate the relay.
so now we have the third vertical line which is pin 30. This is the pin that will receive battery power (+) (from the battery directly or some other power source, sometimes ACC power (Accessory power, you know the stuff that only works when you move the key one position, such as your radio, headlights, etc.)
So basically once there is a current that passes from 86 to 85, the relay will "click" and channel the power that is going from the 30 pin into the 87 pin, which will then light up the foglights or whatever accessory you're trying to power up.
As with the middle pin, the 87a, if you were going to use the 5 pin as a 5 pin, then you'd just hook that up to something that you want to be running all the time. This would be in the case of a sidemarker light that lights up with the parking lights, but then also flashes when you signal. The "parking light" mode will be 1 function, and the flashing mode will be another function. This is why you use pin 87a (and that's why it's 87 and 87a, because basically they do the same thing, but at different times). or something like that.
*note* you can wire up a relay to work either 1)switched ground or 2)switched power.
If I don't make sense, it's normal because I get confused about this shit sometimes. Perhaps I'll draw a diagram one of these days.
edited