Do you mean:
1. electrical relay, an electromechanical switch,
2. data relay, sending data from one node to another, or
3. some other use of the word "relay"?
Clarification, please
Swap the relay with another like relay.
Swap the relay with a known good relay.
Swap it with another like relay.
Swap the fan relay with another like relay.
Swap the relay with another like relay.
To check the fuel pump relay on a Volvo 940, first locate the relay, which is typically found in the engine compartment fuse box. Remove the relay and inspect it for any signs of damage or corrosion. You can test it by using a multimeter to check for continuity or by swapping it with a known good relay. If the relay is functioning, check the wiring and connections for any faults before concluding the diagnosis.
automotive relays
in order to check the main relay you must have a multi-meter. then you will have to pull the main relay and check it to see if there is any power going threw it. if yes then its something else if no its like a $10 fix.
check power to horn - no power to horn -check ground -no power to horn -check relay - no power to relay -check fuse inside car first thing -still no power to relay -check horn button -still no power - possible break in wire
The check engine light is not controlled by a relay, the bulb is grounded directly by the engine computer.
Do it have power through it? Check for relay Do it have power through it? Check for relay
The way you check to see if an under voltage relay is wired properly is to disconnect the electrical supply. If the device that is connected to the load side of the relay does not start up or energize when the electrical supply is reconnected, then the relay is connected correctly.