by changing it.
To change out a fan relay for a 1993 Mercury Topaz, locate the relay, typically found in the engine compartment near the radiator. Disconnect the negative battery cable, remove the old relay, and insert the new one in its place. Reconnect the negative battery cable and test the fan to ensure the new relay is functioning correctly.
Test the relay and the temperature sensor.
Apply 12 volts directly to the fan motor. If it runs it is good. If so look at the thermal relay, as it may be bad.
You should be able to switch the relay with the horn relay and then check to see if the horn works.
To replace the high beam relay in a 1985 Volvo 240 DL, first, locate the relay panel, which is typically found under the dashboard on the driver's side. Remove the old relay by pulling it straight out of its socket. Insert the new relay firmly into the same socket, ensuring it is seated properly. Finally, test the high beams to confirm that the replacement was successful.
easiest way to check is to cover grill in front of radiator and start engine cover will restrict air flow and make engine heat up.by watching temp gauge you should have a fair idea when fan should switch on.if it doesnt switch on you know relay or swith is not working. you can then check switch with a test light to see if it has poer on both sides. pretty much test relay the same way relay will only test when hot enuff to turn on fan
there is no real way to test a fuel pump you just haft to listen to it. When you turn your key over you should hear it kick in. Listen for it to click and relay from the switch to the pump. Other than that you have no way to test it.
under the hood on passenger side there will be three relays one is the blower fan relay unplug them one by one and test them to see which has a current when you turn the fan on
There is no time frame for replacing a relay. You will only need to replace one if it goes bad. Then you can test it by replacing it with a different relay from a different plug that is the same type, and that you check to see what that one will affect. hope this helps.
If you suspect a problem, radiator shops can run a "flow test" after you remove the radiator and take it to them. If you don't want to remove and replace the radiator, they'll also do that part for you.
The quickest & easiest way to test a relay is by substitution. It can be bench tested using wires and a test lamp.
Remove The Radiator And Have A Radiator Shop Test, And Flush It.