Raditor Fans Not Working
07-23-2015, 11:25 AM
#1
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Join Date: Sep 2013
Location: Spartanburg, SC
Posts: 56
Raditor Fans Not Working
This just started...the car cools fine while in motion, once up to temp, if the car has to idle for a period of time, stuck in a traffic jam or at a drive thru window line, the temp gage starts rising and will overheat if I don't catch it. How do I tell if it is the temp sensor (and where is that sensor?) or if it is one of the (I count 3) relays?
Any and all help is greatly appreciated! I have a '95 SE auto with 264K if that helps.
Any and all help is greatly appreciated! I have a '95 SE auto with 264K if that helps.
Last edited by peb396; 07-23-2015 at 11:29 AM.
07-23-2015, 03:55 PM
#3
Do the radiator fans come on when you turn the a/c on?
First, take a hold of the fan blade and see if it wiggles. The amount of wiggle that is permissible is ZERO. If you have any wiggle, replace the fan. Check both fans.
If the fans pass the wiggle test - In the fuse block under the hood next to the battery, check the 2 radiator fan fuses. The cover has them labeled "FL30A RAD FAN 1 and "FL30A RAD FAN 2". These are 30 amp fuses.
If the fuses are OK then pull out RAD FAN 1 relay and replace it with either RAD FAN 1 OR RAD FAN 2 relay, your choice.
If the fans don't work after this, you will need to dig deeper into this.
First, take a hold of the fan blade and see if it wiggles. The amount of wiggle that is permissible is ZERO. If you have any wiggle, replace the fan. Check both fans.
If the fans pass the wiggle test - In the fuse block under the hood next to the battery, check the 2 radiator fan fuses. The cover has them labeled "FL30A RAD FAN 1 and "FL30A RAD FAN 2". These are 30 amp fuses.
If the fuses are OK then pull out RAD FAN 1 relay and replace it with either RAD FAN 1 OR RAD FAN 2 relay, your choice.
If the fans don't work after this, you will need to dig deeper into this.
07-24-2015, 03:53 PM
#6
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Join Date: Sep 2013
Location: Spartanburg, SC
Posts: 56
Got back early...both fans come on with a/c...
...no fan 'wiggle'...
...both fuses next to the battery are good...
...don't know how to check relays with voltmeter, but have one and will be looking at that in a minute...
...flipped the two relays and still didn't work...put them back where they were originally...
...replaced the one different relay with an intermodal (new) still not working...
...have a temp sending switch that I am about to start reading Haynes about...
...what else?
...no fan 'wiggle'...
...both fuses next to the battery are good...
...don't know how to check relays with voltmeter, but have one and will be looking at that in a minute...
...flipped the two relays and still didn't work...put them back where they were originally...
...replaced the one different relay with an intermodal (new) still not working...
...have a temp sending switch that I am about to start reading Haynes about...
...what else?
07-24-2015, 10:16 PM
#7
Do the fans run when you turn on the a/c? They are supposed to. I kind of expect that you will tell me that they don't.
Right now I am leaning towards the possibility that you have 2 burned out radiator fan motors.
It is possible that the wire harness between the relay box by the battery and the radiator fans themselves could have been damaged, but the damage would have to have cut several wires. I don't feel that wiring is the problem here.
What we need to do is see if 12 volts is getting to the radiator fans and that there is also a ground connection. You will be doing 2 things with the voltmeter, measuring for 12 volts and checking wire continuity.
So with the car turned off, unplug the wire harness connector for either one of the fan motors. In the connector that is on the car's wire harness, check continuity on the black wire to ground. You use the ohm scale of the meter for continuity, one meter lead ton the black wire and the other on the battery negative terminal. If you have continuity, the meter will read zero ohm. I suppose 1 ohm or less is acceptable.
If you have continuity, then we will check for 12 volts going to the fan motor.
For this, you need to start the car and turn on the a/c. Leave the fan unplugged. Mane sure your meter is on DC volts. Connect the negative lead of the meter to the negative terminal of the battery. In the wire harness connector, check the white with black stripe wire for 12 volts. Make sure you have the black stripe wire and not the blue stripe wire.
If you have 12 volts, actually more like 14 volts because the alternator is charging, the fan is getting the power to run and you have a burned out fan motor.
Right now I am leaning towards the possibility that you have 2 burned out radiator fan motors.
It is possible that the wire harness between the relay box by the battery and the radiator fans themselves could have been damaged, but the damage would have to have cut several wires. I don't feel that wiring is the problem here.
What we need to do is see if 12 volts is getting to the radiator fans and that there is also a ground connection. You will be doing 2 things with the voltmeter, measuring for 12 volts and checking wire continuity.
So with the car turned off, unplug the wire harness connector for either one of the fan motors. In the connector that is on the car's wire harness, check continuity on the black wire to ground. You use the ohm scale of the meter for continuity, one meter lead ton the black wire and the other on the battery negative terminal. If you have continuity, the meter will read zero ohm. I suppose 1 ohm or less is acceptable.
If you have continuity, then we will check for 12 volts going to the fan motor.
For this, you need to start the car and turn on the a/c. Leave the fan unplugged. Mane sure your meter is on DC volts. Connect the negative lead of the meter to the negative terminal of the battery. In the wire harness connector, check the white with black stripe wire for 12 volts. Make sure you have the black stripe wire and not the blue stripe wire.
If you have 12 volts, actually more like 14 volts because the alternator is charging, the fan is getting the power to run and you have a burned out fan motor.
07-24-2015, 10:27 PM
#8
Regarding the temperature sending switch, if the radiator fans don't run when you turn on the a/c, the temperature sending switch is not the problem.
Don't worry about testing the relay. You did the relay swap and nothing changed. Relays very, very seldom go bad. The chances of having 2 bad relays so that the swap didn't work is getting towards the odds of winning the lottery.
Don't worry about testing the relay. You did the relay swap and nothing changed. Relays very, very seldom go bad. The chances of having 2 bad relays so that the swap didn't work is getting towards the odds of winning the lottery.
07-25-2015, 02:52 PM
#10
I really didn't expect the fans to run with the a/c. But that is good because it rules out a few thing and more importantly, points us in the direction we need to go.
It could be the ECTS. Measure the resistance of the ECTS. You can do it without removing the sensor. Do this with the engine at operating temperature or warmer. The engine does not have to be running. Remove the wire harness plug from the ECTS. Set your meter to measure ohms and connect the meter leads to the contacts of the ECTS.
A good ECTS will have a resistance of between 235 to 260 ohms when the engine coolant is at 200º F (93º C). The hotter the temperature, the less resistance. If you get a reading of 2K ohms or higher on a hot engine, the sensor is no good. A 2K reading would be OK on a cold engine. At 32ºF (0ºC), the resistance should be about 6K ohm.
It could be the ECTS. Measure the resistance of the ECTS. You can do it without removing the sensor. Do this with the engine at operating temperature or warmer. The engine does not have to be running. Remove the wire harness plug from the ECTS. Set your meter to measure ohms and connect the meter leads to the contacts of the ECTS.
A good ECTS will have a resistance of between 235 to 260 ohms when the engine coolant is at 200º F (93º C). The hotter the temperature, the less resistance. If you get a reading of 2K ohms or higher on a hot engine, the sensor is no good. A 2K reading would be OK on a cold engine. At 32ºF (0ºC), the resistance should be about 6K ohm.
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