It's your coolant temperature sensor relay unit. It's a black box that has an 8 pin plug going into it. It's located behind the glove box to the center of car, on the metal frame part. It's a real pain to get at a pick n pull or junk yard since they constantly fail. Good luck.
That one should run anytime the a/c is turned on.
Not necessarily. It's more likely a problem with the engine's cooling system: * improperly maintained coolant levels or quality * corroded and clogged radiator * faulty radiator cap * faulty water pump And if it's a newer vehicle with electric cooling fans, you should check to see that the secondary fan starts when the AC is turned on.
The radiator cooling fans are turned on when the heater control is set to defrost.This makes for better and more effective defrosting of the windshield
Could be a bad temperature sensorUsually located at the rear of the radiator about 1/3 down from the top
Because quite a lot of the energy used by a combustion engine gets turned into heat whether we want it or not, so a cooling system is needed to keep the engine from overheating.
When air conditioning or front defroster are turned on it will turn on A/C compressor which requires the A/C condensor to be cooled (via radiator fan).
The 1999 Saturn S-Series engine heats up the coolant, the thermostat valve opens and the coolant circulates between the radiator and the engine. Then the radiator fans turn on to cool it back down. The fans are also turned on when the air conditioner is turned on to aid in cooling the radiator and the air conditioner condensor.
Ask your mechanic to check out your electronic sensor. I had the same thing happen, and after replacing the radiator and other parts of the cooling system, it turned out to be the fan sensor.
WHY MY ECU 15AMP FUSE BLOWS EVERYTIME I START MY 97 ACURA INTEGRA
There are two motors which drive two separate fans on the CR-V radiator. One is the regular cooling system fan and it is operated by a temperature sensing switch in the coolant system that monitors the coolant temperature. When the coolant reeaches a certain temperature the temperature sensing switch turns on the current to the cooling fan. When the coolant temoperature falls below a certain temperature the switch shuts the fan off. The other fan is the fan that is controlled by the vehicle cabin air conditioner. When the A/C is turned on the fan comes on automatically with the a/c.
Either the radiator is partially plugged and t he system has been designed marginally ( they do that to save money you know ! ) so that when the heater is turned on most of the water gets routed through the heater core, bypassing the radiator and causing overheating, or the system is just designed marginally and as above. You can put your hand on the radiator grille and feel it from the front of the car ( using all due caution, of course ) and see if there are any sudden temperature changes from hot to cold. A cold spot indicates a plugged section. The only solution to this is to replace the radiator. And/or you can also put a restriction in the line feeding the heater core, so that more water will flow through the radiator. If your car has worked well in the past with the heater turned on, then I would suspect a partially plugged radiator. I've changed these myself, and it's not hard. Make sure you don't have any other systems bonded to the radiator for cooling, like power steering, a/c , etc. Good Luck !!
The radiator drain is turned counter clockwise to loosen.