Overheating
4 Answers
You need to check is fan burned out? Temp sensor on engine bad? Or fuse bad . Begin here.
migration_Lastchance... answered 8 years ago
Try this. start the engine and let it warm up for just a few minutes. The coolant fans should be OFF. Now turn in the AC System to.max and high blower speed. The AC system of course should work...and...the coolant fans should be running. This proves the fans function as designed and relays and switches work. HVAC SENSORS would then have to be checked. BTW...did you notice any WARNING LIGHTS ON when the engine is running? Is the AC Light flashing?
RobF_HomeMech answered 8 years ago
Q: My fans are not working that's where my radiator it is at. Where is the relay switch? A: Many Toyotas have a belt driven fan, that is the primary source to pull air through the radiator to cool the coolant flowing through it as it returns to the engine block. Those that don't have a belt driven fan will usually have two electric fans. In this case both fans should come on when the engine is started. Many, especially larger engine vehicles will also have an electric fan in addition to the mechanical fan. This additional fan, referred to as the auxiliary or condenser fan is located in front of the radiator and AC condenser (looks like a second radiator in front of the radiator.) The auxiliary/condenser fan serves two purposes. When the AC is turned on it provides additional cooling for the condenser, ensuring you have as cool/cold as AC as possible, especially when the car is stationary. It also serves as auxiliary cooling for the radiator when the engine is at high temp, especially on hot days or after long drives and the vehicle is stopped/at idle. Your entire cooling system can be fine, but under these conditions, if the auxiliary/cooling fan is malfunctioning, the vehicle will overheat at idle. First thing to do is check the fan. It's a simple 12 volt motor, disconnect the connect from the fan and jumper it to a 12 volt source (pins don't matter, it will turn one direction or the other if it's working.) If the fan is bad, replace it. An OEM one from a wrecking yard is about $75. If the fan is good, check the condenser fan relay (labeled CDS fan,) in the relay/fuse box nearest the firewall on the driver's side of the engine compartment. These can be very expensive, depending on your attitude, you might get one for free at a wreaking yard (don't forget to tip the "yard mechanic," doing so goes far in your dealings with them - $5 will do it... cheap compared to a dealer part this is $50...) Replace your (hopefully free, or nearly so,) relay. To test it, turn on the AC and crank it to COLD on the temp and medium on the interior fan, the aux/condenser fan should be on. If it is, but the vehicle is overheating, turn your AC on, this will kick on the condenser fan, now you know the temperature sensor in the cooling system is probably the culprit, after that, I hear there is an CPU... that's gonna be pricey. Good luck!
RobF_HomeMech answered 8 years ago
Agree with MikBek, don't overlook the fuse...