There can be many relays on a vehicle. We need to know which one and what vehicle you have.
Check Owner's Manual. If you do not have one. Check Related links below.
Swap it with another like relay.
Swap the relay with another like relay.
what does a flasher relay in 2000 dodge durango look like.
Swap the fan relay with another like relay.
Swap the relay with another like relay.
good
check out the relay
check fues if not bad ckeck relay if not relay check blower moter by hooking it up direct to a power source.
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.
Look at your realys next to your battery and check them all
Most are cubical in shape.