What is pin 87 on a relay?
Numbers of a Relay Note that each pin is numbered. 85 and 86 are the coil pins while 30, 87, and 87a are the switch pins. 87 and 87a are the two contacts to which 30 will connect. If the coil is not activated, 30 will always be connected to 87a. Think of this as the relay in the Normally Closed (OFF) position.
Are all 12V relays the same?
The problem is, not all relays are the same. Just because it has the same number/location of terminals, doesn’t mean the relay works for that application. Some relays, when used for the wrong application, can generate a voltage spike over 100V on a traditional 12V system.
What is 85 and 86 on a relay?
85 will be used to ground your relay, while 86 will be connected to the switchable power. 87 and 87a will be connected to your controlled accessories that you wish to turn on and off with your relay.
What is the difference between 4 and 5 pin relays?
The difference between a 4 and 5 pin relay is that a 4 pin relay is used to control a single circuit, whereas a 5 pin relay switches power between two circuits. 4 pin relays use 2 pins (85 & 86) to control the coil and 2 pins (30 & 87) which switch power on a single circuit.
Why is a relay clicking?
As I have stated several times previously, every mechanical relay has a little electromagnet in it, and when it is energized it pulls the internal switch contacts together. That makes an audible clicking sound. You also can feel the contacts closing if you lay your hands on the relay.
What is pin 85 on a relay?
Note that each pin is numbered. 85 and 86 are the coil pins while 30, 87, and 87a are the switch pins. The great thing about relays is that you can set 87 and 87a to be either open or closed, depending on how you need the switch to work. If you want a closed relay, you will want to wire to 87a.
Does a relay click when it’s bad?
If your starter relay has gone bad, the electrical signal will never make it from the battery to the starter motor. As a result, your engine won’t turn over – no matter how many times you turn the key. A faulty relay often produces an audible clicking sound when you turn your car.
What are the 2 circuits of a relay called?
Relays involve two circuits: the energizing circuit and the contact circuit. The coil is on the energizing side; and the relays contacts are on the contact side. When a relays coil is energized, current flow through the coil creates a magnetic field.
Why would you use a 5 pin relay?
A normally closed relay will switch power OFF for a circuit when the coil is activated. 5 pin relays provide 2 pins (85 & 86) to control the coil and 3 pins (30, 87 & 87A) which switch power between two circuits. When the coil is activated, power will be switched from the normally closed pin to the normally open pin.