alright heres my problem, the car was overheating so i replaced the thermostat and everything seemed to be fine, but then it started overheating again and i realized as soon as i turned on the a/c the engine would cool down, so i came to the conclusion it was the fan. so i started the car and let it run for a while and the engine fan never kicked on. it comes on when the a/c fan is running, but not when the a/c is off. i checked all the wiring and everything seems to be good, no burnt fuses or anything. what could it be, and how can i fix it? -Todd
Star Stage II, Greddy Type S, ADFX 3" DP, blah blah blah
#86980, "RE: Radiator fan not turning on?" In response to Reply # 1
Yeah dude. The fans don't turn on, so the ECU is bad? No. That's totally ridiculous.
Jumper the center peg on the condensor fan relay to the center peg on the radiator fan's low speed relay and turn your AC on. if the fan comes on, at least you know the fan itself isn't bad.
Now, the fan's function is controlled by coolant temp. Can you verify the coolant temp sensor is plugged in, and that its resistance is within spec? I believe it's 11K ohms at 70* and 8-900 Ohms at operating temp. Check it with a multimeter.
______________________________ If a sentence found online has 35% misspellings or greater and includes at least two racially charged expletives, chances are it is a YouTube comment.
'95 Eclipse TurboGS (garage deco) '95 TSi AWD (restoring a survivor) '97 Talon ESi-T (poor impulse control) '99 Eclipse RS-T (daily beater) '13 Evo X (mostly stock) '17 Sienna (Middle Aged Dad Mobile)
#86983, "RE: Radiator fan not turning on?" In response to Reply # 2 Mar-11-05 11:26 AM by MitsuEclipseGS
I have noticed that the fan will come on every once in a while, but other times it wont come on and it will overheat. where is the coolant temp sensor located at? -Todd
Star Stage II, Greddy Type S, ADFX 3" DP, blah blah blah
#86987, "RE: Radiator fan not turning on?" In response to Reply # 3 Mar-11-05 11:53 AM by XtremeRS
The fan relay is under the hood fusebox, so you may want to check that also..The relay could be bad, or the relay pins are corroded..Just as info, the driver side fan should kick on at around 206 degrees, from many datalogged runs i've done. The pass side fan should come on with the AC and when coolant temps get approx 212 or so..
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#86999, "RE: Radiator fan not turning on?" In response to Reply # 5 Mar-11-05 01:21 PM by XtremeRS
Originally posted by MitsuEclipseGS i found the coolant temp sensor, what does the relay look like? -Todd
The location of the relay should be printed right on top of the fuse box lid. The relay is a black, square/rectangular shaped looking plastic box, so to speak.. If you still cant get it to work, then you will need to test if the ECU is actually sending a signal to the relay to turn it on, and also, if the relay is sending out power to the fan. You will need a multimeter to do this..The ECU sends a ground to the relay to turn it on, and then you should have power at your fan..Also, you may be able to feel the relay "click" on, then you can test to see if its sending power to the fan. There should be at least 2 of the same relays there in the fusebox, so try switching the fan relays(there is one for each fan), and see what happens.
13.5 @108 MPH-2.2 60ft(stupid FWD!) S16G @ 18 PSI/FMIC/Running on MegaSquirt II (Now with sequential fuel injection) My webpage: http://eclipsed4evr.home.comcast.net -1998 Mitsubishi Eclipse RS-T- "Toy" -1992 Plymouth Laser Turbo AWD(SOLD) -2000 Honda CR-V(daily)
#87028, "RE: Radiator fan not turning on?" In response to Reply # 2
Originally posted by DarkOne Yeah dude. The fans don't turn on, so the ECU is bad? No. That's totally ridiculous. Jumper the center peg on the condensor fan relay to the center peg on the radiator fan's low speed relay and turn your AC on. if the fan comes on, at least you know the fan itself isn't bad. Now, the fan's function is controlled by coolant temp. Can you verify the coolant temp sensor is plugged in, and that its resistance is within spec? I believe it's 11K ohms at 70* and 8-900 Ohms at operating temp. Check it with a multimeter.
It might be ridiculous on the Eclipse but on an Evo this can be the case. I have an EMS in there now but this controls the fans especially at startup and idle. When the EMS is in downlowd mode(logs) the fans stay on because the ecu doesnt fully function when transfering data. Some people have also had bad basemaps which didnt allow the fans to turn on and casuing overheating. So his idea is not that far off.
#87049, "RE: Radiator fan not turning on?" In response to Reply # 2
Originally posted by DarkOne Yeah dude. The fans don't turn on, so the ECU is bad? No. That's totally ridiculous. Jumper the center peg on the condensor fan relay to the center peg on the radiator fan's low speed relay and turn your AC on. if the fan comes on, at least you know the fan itself isn't bad. Now, the fan's function is controlled by coolant temp. Can you verify the coolant temp sensor is plugged in, and that its resistance is within spec? I believe it's 11K ohms at 70* and 8-900 Ohms at operating temp. Check it with a multimeter.
The ECU might not be the problem on his car but its definitely possible. Its not ridiculous. It was the problem on my car when the fan wouldn't turn on.
#87087, "RE: Radiator fan not turning on?" In response to Reply # 8
Originally posted by pr0 The ECU might not be the problem on his car but its definitely possible. Its not ridiculous. It was the problem on my car when the fan wouldn't turn on.
I just don't believe that. The fan functions are so simplistic i just can't see an ECU failing in that way and not showing other symptoms first. This is like saying you're having a motherboard failure because the HDD LED on the case doesn't light up anymore.
Originally posted by gofaster87 It might be ridiculous on the Eclipse but on an Evo this can be the case.
Well, it is an Eclipse we're talking about, after all..
______________________________ If a sentence found online has 35% misspellings or greater and includes at least two racially charged expletives, chances are it is a YouTube comment.
'95 Eclipse TurboGS (garage deco) '95 TSi AWD (restoring a survivor) '97 Talon ESi-T (poor impulse control) '99 Eclipse RS-T (daily beater) '13 Evo X (mostly stock) '17 Sienna (Middle Aged Dad Mobile)
#87092, "RE: Radiator fan not turning on?" In response to Reply # 9
its your coolant temp sensor, cuz when you turn on the AC it kicks both fans on, i had this problem, check/replace the sensor and you will not only not overheat, your gas mileage will go up cuz it wont constantly be in openloop cold-start mode!
2005 Legacy GT Ltd, Garnet Red Pearl speak softly and spool a big turbo
Search
Printer-friendly copy
0 Users in Chat
