Passenger Radiator Fan
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Joined: Jul 2008
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From: Atlanta Georgia USA
Passenger Radiator Fan Once I turn on the AC, the drivers's side comes on without any problem. However, the passenger side radiator fan will not come on for ANYTHING! Not even when the car's temp is at 220+ degrees. What gives?
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Joined: Dec 2017
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From: Bossier City, Louisiana
Bad fan? Apply 12 volts to it directly and separately from the other to see if it works. Is the suspect fan controlled by the same relay as the other or does it have a different relay?
Rick
Rick
Teching In
Joined: Mar 2017
Posts: 45
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From: Peachland, NC
First thing I would check is the fuse box. It should show the location of the fuses and relays for the fans. There may be a separate fuse for each fan or dual relays (probably are not but just incase). Check the fuses and swap relays if they are twin circuits. Check your wires running to the fans for any signs of damage. Right now does the driver's side fan come on based on temperature with out the a/c on? It has been my experience that on dual fan or two speed set-ups that one stage is the primary fan that comes on first (or on low speed) when the car does not need max cooling and when the a/c kicks on or the temperature gets high enough the second or high speed stage is triggered. Some of them I have seen will not activate the second stage until the car is pretty warm (215+). If the passenger fan runs with a direct 12v applied but the driver fan does not come on based on temperature alone then your problem will probably be the fan switch or a temperature sending unit. Worst case scenario is it could be ecm/bcm related where the computers are getting the right signal from the sending units but are not sending the command to turn the fans on. The a/c has a physical switch that cuts the second stage on independently and overrides the computer control.
My bet is probably a bad fan motor or a bad fuse/wire/relay in the harness running to it.
My bet is probably a bad fan motor or a bad fuse/wire/relay in the harness running to it.
Teching In
Joined: Mar 2017
Posts: 45
Likes: 2
From: Peachland, NC
So your motor is good then. Does the driver side come on when the engine is hot without the a/c switch being on? If it does then check your wiring, fuses, etc. for the passenger fan. If it does not come on then look for the problem in either coolant temp sensor or radiator fan switch. Not sure which our cars have. Some cars have both, some only one.
Thread Starter
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Joined: Jul 2008
Posts: 703
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From: Atlanta Georgia USA
First thing I would check is the fuse box. It should show the location of the fuses and relays for the fans. There may be a separate fuse for each fan or dual relays (probably are not but just incase). Check the fuses and swap relays if they are twin circuits. Check your wires running to the fans for any signs of damage. Right now does the driver's side fan come on based on temperature with out the a/c on? It has been my experience that on dual fan or two speed set-ups that one stage is the primary fan that comes on first (or on low speed) when the car does not need max cooling and when the a/c kicks on or the temperature gets high enough the second or high speed stage is triggered. Some of them I have seen will not activate the second stage until the car is pretty warm (215+). If the passenger fan runs with a direct 12v applied but the driver fan does not come on based on temperature alone then your problem will probably be the fan switch or a temperature sending unit. Worst case scenario is it could be ecm/bcm related where the computers are getting the right signal from the sending units but are not sending the command to turn the fans on. The a/c has a physical switch that cuts the second stage on independently and overrides the computer control.
My bet is probably a bad fan motor or a bad fuse/wire/relay in the harness running to it.
My bet is probably a bad fan motor or a bad fuse/wire/relay in the harness running to it.
Now,I just tested it (again) to see if the drivers side would come on by temp alone, it never did. So both were not running. Soon as I cut the A/C on, the driver's side fan is activated. I even called myself checking the relays, and heard the clicks.
Thread Starter
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Joined: Jul 2008
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From: Atlanta Georgia USA
"So your motor is good then. Does the driver side come on when the engine is hot without the a/c switch being on? If it does then check your wiring, fuses, etc. for the passenger fan. If it does not come on then look for the problem in either coolant temp sensor or radiator fan switch. Not sure which our cars have. Some cars have both, some only one."
so can the temp sensor go bad without it even showing on my OTC OBD reader? Cause it never showed, until of course I unplugged the sensor.
But I tell what is now showing, the damn throttle actuator code (P2118)
SMH my car is having her 100,000 mile problems! LoL
so can the temp sensor go bad without it even showing on my OTC OBD reader? Cause it never showed, until of course I unplugged the sensor.
But I tell what is now showing, the damn throttle actuator code (P2118)
SMH my car is having her 100,000 mile problems! LoL
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Teching In
Joined: Mar 2017
Posts: 45
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From: Peachland, NC
Does your OTC just act as a code reader or is it a scanner? Your sender could be bad and sending the computer the wrong signal. If it reads low it may not set off a fault code because the computer sees the data but it may not see enough temp to call for the fans. If your tool can scan real time readings you can actually see what the computer is seeing.
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