How to test a 4 pin relay with multimeter

1. How do you tell if a relay is bad with a multimeter?
2. How do you test if a relay is bad?
3. How do you check a relay with a multimeter?
4. How do 4 pin relays work?
5. How many Ohms should a relay read?
6. How many Ohms is a bad relay?
7. What are the common faults of relays?
8. What pins to jump on relay?
9. Can I use a 5 pin relay instead of a 4 pin relay?
10. How do you test a fuel pump relay with a voltmeter?
11. How many volts should a fuel pump relay have?
12. Can I bypass fuel pump relay?

How do you tell if a relay is bad with a multimeter?

Take the leads of the multimeter and connect them across the coil terminals of the relay. For a normal coil, the multimeter should read anywhere between 40Ω to 120Ω. If the coil is damaged i.e., it is open, the meter shows out of range and you have to replace the relay.

How do you test if a relay is bad?

The only tool required to check a relay is a multimeter. With the relay removed from the fuse box, the multimeter set to measure DC voltage and the switch in the cab activated, first check to see if there are 12 volts at the 85 position in the fuse box where the relay plugs in (or wherever the relay is located).

How do you check a relay with a multimeter?

Grab a multimeter and set it to Ohms. Touch the leads across the electromagnet coil pins and measure resistance. Anywhere from 50-120 ohms is OK. Out of range or open means a bad electromagnet coil winding and time for a new relay.

How do 4 pin relays work?

4 Pin Relay

4 pin relays use 2 pins (85 & 86) to control the coil and 2 pins (30 & 87) which switch power on a single circuit. There are 2 types of 4 pin relay available; normally open or normally closed. A normally open relay will switch power ON for a circuit when the coil is activated.

How many Ohms should a relay read?

The relays are usually supplied with 12 V directly from the vehicle battery. The electrical resistance (impedance) of the coil is vary and is different depending upon the manufacturer of the relay as well as relay's type, but in general a typical value should be expected between 50 ohms and 200 ohms.

How many Ohms is a bad relay?

Put the multimeter in the Ohms setting to measure resistance and place your probes on the two normally open switch pins typically labeled ”85” and ”86”. An “O.L” reading or any value from the meter that is not between 50Ω and 200Ω means the relay may be faulty.

What are the common faults of relays?

The two most common failure mechanisms of relays are contamination and mechanical wear of the internal switching elements discussed as follows: a. Contamination is a major cause of early life failures.

What pins to jump on relay?

If the circuit passes the high current (load side) tests, you should be able to simply jumper across terminals 30 and 87 to fire up the device.

Can I use a 5 pin relay instead of a 4 pin relay?

Some 5 pin relays are SPDT (switch between the two pins) and some are DPST (like the main relay- connect 2 pins at the same time.) If you want to use a 5 pin in place of a 4 pin, you shouldn't have to remove the pin. The socket should be the same, but the center pin won't have a contact in it.

How do you test a fuel pump relay with a voltmeter?

With the fuel pump relay removed, install the fuel pump relay tester. Take the multimeter and attach it to a ground. Put the voltage on for 12V to test the ground, and then go back to resistance. There should be less than 5 ohms for this test.

How many volts should a fuel pump relay have?

A voltage of at least 12.5 – 13.0 volts must be present when the engine and pump are running. If the measured voltage at the terminals or the plug of the pump is significantly lower than the on-board voltage, e.g. lower than 11 volts, there is a malfunction.

Can I bypass fuel pump relay?

You could drive with a bad fuel pump relay by bypassing the relay with a jumper wire and running the fuel pump direct. I don't advise doing this unless it is an emergency. The relay is in the system for a good reason so leave it alone unless it is an emergency.