mustangIIfan

my 2.3 is experiencing some heating up issues, i had this problem last year and took it in to service. the car was stalling would not restart and fan would not work. and i was informed the IRCM was faulty and 250 later it was replaced with brand new. last week i had just performed a heater core replacement (due to leaking coolant on my floor and smell of coolant coming through the vents) and while i was running it to see if i had heat i noticed the gauge was getting high into the "R" on NORMAL usually it would run in the "A" or "L" (i know it seems like its overcooled but it also got brand new radiator last year too) if it got to the "M" the fan kicked on and brought it back down, now im confused why it quit working again. i jumped the fan and it works, and while doing the core job i broke the old temp sensor mounted on the heater hoses going into the firewall so that was replaced any suggestions?

skunk21

since you jumped the fan and the motor works next step is to continue checking the fan circuit. you want to check the temp sensor/switch by running a resistance test and doing a voltage test on both sides of the relay. also check all the wiring and connections.

mustangIIfan

ok can you explain a little more on how to do these tests?

mustangIIfan

also my car has A/C but it didnt work so i removed the compressor, dryer, belt, and hoses it still has condenser and evaporator in it. i heard when you turn a/c on it turns the fan on and leaves it on until you turn off a/c. if this is true can i still turn my a/c switch on to see if fan will turn on?

skunk21

you need a multi meter. to test the resistance set it to the 20K range. Has the coolant warms up this will cause the resistance to decrease the colder the coolant the higher it is., you can also take it out and make a pig tail and put the sensor in hot water. example temp of 194* resistance should be 2.80, 212* resistance of 2.07. you can use a test light or the meter to verify power to the relay, also check your fuse.

mustangIIfan

ok i think i have figured it out but need help. first i dont think i have a problem with fan not working, when i replaced the heater core i didnt put back enough coolant and the engine temp would go up and back down so i ran engine and topped off as needed now its filled, i then noticed the engine will not warm up to normal operating temp, doing some research i discovered when the coolant temperature reaches 210° the ECC signals the IRCM to turn on the radiator cooling fan. Once the temperature drops below about 190°, the fan is shut off. If the temperature exceeds about 220° , the ECC also tells the IRCM to turn on the cooling fan. The shut-off temperature for this fan is around 200°. Additionally, when the air conditioning compressor is turned on, the ECC will cause the IRCM to energize the primary fan but the car runs at maybe 160* how can i warm the engine up more to actually see if the fan will activate? its winter here so i cant actually get in it and take it for a drive im kinda scratching my head with me already putting in a new temp sender and thermostat

skunk21

It is also possible the IRCM has gone bad.even though the motor kicked on when you put power to it the motor can still be bad. A bad motor pulls too many amps and can wreck the IRMC. I would test the draw on the fan motor but you need to know the basic specs of the motor . I woul drun this test before changing out the module or there is a good chance it could fry it again ( if it is the motor or just a bad module you need to figure this out).

You could also run codes of it see if code for ect ( engine coolant temp ) comes up but imo go over the circuit again.