My radiator far does not work,i check the fan and relay both are good,now my a/c fan stop working,,

If you see pin 87 you must see 30 ! 30 should have B+ voltage as will 86 . Pin 85 is to the engine computer ,PCM/ECM . If you jump to pin 85 you run the risk of frying the PCM on that circuit . A transistor inside the PCM is switched on when the engine temp gets to hot . The PCM supply's a ground for the control side of the relay energizing the relay an closing the contacts inside the relay sending B+ voltage from pin 87 to pin 30 to the fans ! Go to you tube an check out video on relay's an how they work .

you should check fuses first if its been working good then i would dought if fuse jumped OUT of fuse box , there is a fan relay also , could be bad . swap out relay with a good one see if it works. you can also check temp sensor that tells fans to come on . good luck .

Check cooling fan relay. Check your owners manual for location and discription. This might have been you problem to start with or when your first fan failed it may have damaged the relay. If you dont have an Obd II scanner. Try resetting your cars computer by removing negative battery terminal for 60 secs. then replace terminal. See if this works for you. Try to reset computer first then check relay. Good luck. Battery may be in the trunk.

SOUND LIKE ENGINE COOLANT FANS NOT RUNNING.CHECK TO SEE IF COOLANT FANS RUNNING WHEN ENGINE START OVERHEATING.IF NO CHECK COOLANT FANS FUSE AND RELAYS.IF ALL IS GOOD.HOTWIRE COOLANT FANS TO MAKE SURE THEY ARE WORKING.IF NO REPLACE FAN MOTOR.IF FAN RUN WHEN YOU HOT WIRE IT.THE COOLANT TEMPERATURE SENSOR FAULTY ARE THE PCM FAULTY YOU CAN USE A SCANNER TO CHECK THEM FOR FAULT CODE.IF EVERYTHING GOOD SO FAR.REPLACE THERMOSTAT AND RADIATOR PRESSURE CAP FLUSH ENGINE BLOCK AND RADIATOR.CHECK RADIATOR AND CONDENSOR AIR CORES MAKE THEY NOT STOPPED UP WITH LEAVES AND OTHER DEBRIS THAT WILL BLOCK OFF AIR FLOW THROUGH THE FRONT GRILLE RADIATOR CORES.ALSO CHECK WATER PUMP WEEP HOLE IF ITS LEAKING WATER PUMP NEEDS REPLACING.

Did you check the temp sending unit? That tells the computer what the temp is and the computer then triggers the relay. Also, hot wire the fan motor and make sure it runs when it has power.
As far as the radiator "busting open" if it actually did that and didn't just develop a leak, it may indicate a head gasket failure pressurizing the radiator far more than it's normal capacity.

You have to check the main relay fan fuse relay and disconnect the fan and try it directly to make sure the fan motor is fine if all this is well into the cavity where the thermostat is a thermal switch that sends it relay the signal to the fan you can disconnect and the fan has to start working if this works the problem is you have the thermal switch. Thanks

Check to see if the radiator fan relay has gone bad and needs to be replaced. Once you located the relay, (in the fuse box under the hood) Try swapping it out with another relay and see if the fans stop, if the fans stop working with the swapped relay, replace the relay. It's know for the relays when they go bad to stick and will have a close loop. Good luck and hope this helps. Keep me posted, be glad to help you get your car running 100% again soon.

The ECU drives a relay which in turn drives the fan. Trace the fan wiring back to the relay and check the plug connection. Does the fan turn freely by hand? If not, replace it. The fan needs a solid ground connection as well as power from the relay.

Could be a few things. If your fans were just working then just stopped, it could be the fan motor. It could also be the relay. If you know where your lo speed and high speed cooling fan relays are located, you can eliminate this step easily. Take a known working relay (rear defrost or something not essential for starting) and replace the fan relay with the known operational relay while your engine is running and A/C is turned on. If the fans start, there's your problem, if not, then it's probably your fan motors.
Make sure the fuse that protects the fan speed relays is not blown as well.

Your fan switch is probably the part that's not sending a signal to the relays, to start the fans spinning.