testing the fan relay

[biggene]

Is there any way to test this relay? This is the problem. My fan will work if I run a wire directly to the fusebox, but wont work when the circuit is connected like it should be.
I have replaced the fan thermosensor in the radiator, the coolant temp sensor underneath the intake manifold, radiator, water pump, hoses and I still cannot get this thing to come on like it is supposed to from the factory. Can anyone think of anything else it might be??

Thanks,
Gene

[3rdgenhatchDX]

Hey i just tested my g/f's relay in her civic and it wasn't plugged in all the way, take 2 wires and remove the plug from the fan, run the wires to their coordinating battery terminals and see if your fan works, if it does then you don't need to replace it, if it doesn't then the fans your problem, now on to the relay, first to see if your relay is getting juice take the relay and don't plug it in all the way, you should hear it sparking, next take your relay out, and start the car, let it get to normal running temp. plug the relay in and if the fan doens't come on then your relay is shot... DO NOT UNDER ANY CIRCUMSTANCES GO TO THE JUNKYARD AND PULL A RELAY TO PLUG INTO YOUR CAR!!! THIS COULD SCREW IT UP MAJORLY!!! hope it goes well!

[DanG86LX]

Easier if u got a multimeter..
Cooling fan relay (MITSUBA RC-2203) have 4 prongs, 2 cooper like which is NO (normal opened) switch, and 2 tinned like which is the coil ~ 100ohms.
If u connect the coil to a 12V battery u hear the relay click.. U may also check that NO switch closes..

Now if the relay is good, start checking 12V and GND @ plug..
Looking from the passenger side fender, the relay should be plugged into 2nd slot from the bottom or fender.
Where the 4 prongs relay plug into U should see:
- bottom right +12V from batt. If not, check fuse 9 (30A) under hood fuse box.
- bottom left fan motor which look like a small resistor with the multimeter.
- top right +12V only with ignition key on II or normal driving position. If not check fuse 12 (15A) under dash fuse box.
- top left GND through radiator thermo switch, when it is ON.

[Shirako]

That relay is a pain in the ass to find, I couldnt get it anywhere and Honda wanted $60! lol just do what I did and take some heavy guage wire and connect terminals 3 and 2 I believe according to the diagram on the relay, if the fans come on its the relay, I dont actually have the relay in anymore, its just jumped with the wire and the fans are always on for me., I went through the whole replacing everything in the system thing too till I figured out it was the relay lol

[biggene]

well the PO ran a wire straight from the fan connector to the fuse box, so it runs all of the time. But that aint me, I want it to run like it was supposed on a normal circuit. I will try testing the relay and get one from Honda if I find out it is bad.

Gene

[Robs89LXi]

Have you checked your thermostat to see if it is opening?