player1up
05-15-2014, 12:01 PM
I know a radiator cooling fan should cycle, but mine has some odd behavior.
I replaced the coolant temp sensor in the thermostat housing a few weeks ago and for a few days the fan cycled as it should. Turned on at about halfway between 200 and the mark between 200 and 250 on the gauge. Guessing right around the 213° mark
After a couple of weeks it will not come on by itself BUT ( here's where the odd part starts ) will stay on if I turn the A/C on then back off after it's reached the temp it should normally turn on.
Symptom recap:
Rad fan turns on/off with A/C cycle ( along with condenser fan ) when not up to operating temp.
Rad fan will not turn on by temp alone
Rad fan will stay on if I cycle the A/C switch ( condenser fan turns off when A/C is turned off ) when engine is hot enough.
Rad fan will shutoff automatically when temp returns to normal.
Rad fan will turn on if I unplug the temp sensor.
I've tried searching for this on the main forum but I didn't see anything that matched my symptoms.
I'm hoping the computer isn't to blame...
I'll be checking this as well:
Coolant Temp Sensor Response Chart
110 degs = 4.20 volts
120 = 4.00
130 = 3.77
140 = 3.60
150 = 3.40
160 = 3.20
170 = 3.02
180 = 2.80
190 = 2.60
200 = 2.40
210 = 2.20
220 = 2.00
230 = 1.80
240 = 1.62
250 = 1.45
Temperature to Resistance
32 degs = 30 - 35 K ohms
77 degs = 9 - 11 K ohms
212 degs = 640 - 720 ohms
I replaced the coolant temp sensor in the thermostat housing a few weeks ago and for a few days the fan cycled as it should. Turned on at about halfway between 200 and the mark between 200 and 250 on the gauge. Guessing right around the 213° mark
After a couple of weeks it will not come on by itself BUT ( here's where the odd part starts ) will stay on if I turn the A/C on then back off after it's reached the temp it should normally turn on.
Symptom recap:
Rad fan turns on/off with A/C cycle ( along with condenser fan ) when not up to operating temp.
Rad fan will not turn on by temp alone
Rad fan will stay on if I cycle the A/C switch ( condenser fan turns off when A/C is turned off ) when engine is hot enough.
Rad fan will shutoff automatically when temp returns to normal.
Rad fan will turn on if I unplug the temp sensor.
I've tried searching for this on the main forum but I didn't see anything that matched my symptoms.
I'm hoping the computer isn't to blame...
I'll be checking this as well:
Coolant Temp Sensor Response Chart
110 degs = 4.20 volts
120 = 4.00
130 = 3.77
140 = 3.60
150 = 3.40
160 = 3.20
170 = 3.02
180 = 2.80
190 = 2.60
200 = 2.40
210 = 2.20
220 = 2.00
230 = 1.80
240 = 1.62
250 = 1.45
Temperature to Resistance
32 degs = 30 - 35 K ohms
77 degs = 9 - 11 K ohms
212 degs = 640 - 720 ohms