Help with Cooling Fan(s)
Thread Starter
Safety Car
Joined: Feb 2000
Posts: 3,771
Likes: 0
From: MANDEVILLE, LA La
Help with Cooling Fan(s)
My 95's Left Fan is not coming on. When I first purchased it it acted up sometimes it would run and sometimes it wouldn't.I changed all 3 Relay's.Worked fine and I thought I had fixed the Problem. Yesterday with the A/C on the Temp. started to creep up as I was in traffic.Got to 215F.
I stopped and opened the hood and sure enough, the Left Fan was not running. This morning I checked it and the same thing ,No Left Fan.Right side is running on Low and High speeds.Someone along the way,as I am the 3rd owner,re-set the fan's to come on primary 184 and secondary 195 without changing the stock 180F Thermostat.The Fan's have been running forever all the time. I suspect it's the Fan Motor? Am I on the right track as I changed all 3 Relay's.Could it be a PCM Issue? The Right side comes on High when I turn on the A/C.
I stopped and opened the hood and sure enough, the Left Fan was not running. This morning I checked it and the same thing ,No Left Fan.Right side is running on Low and High speeds.Someone along the way,as I am the 3rd owner,re-set the fan's to come on primary 184 and secondary 195 without changing the stock 180F Thermostat.The Fan's have been running forever all the time. I suspect it's the Fan Motor? Am I on the right track as I changed all 3 Relay's.Could it be a PCM Issue? The Right side comes on High when I turn on the A/C.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
My 95's Left Fan is not coming on. When I first purchased it it acted up sometimes it would run and sometimes it wouldn't.I changed all 3 Relay's.Worked fine and I thought I had fixed the Problem. Yesterday with the A/C on the Temp. started to creep up as I was in traffic.Got to 215F.
I stopped and opened the hood and sure enough, the Left Fan was not running. This morning I checked it and the same thing ,No Left Fan.Right side is running on Low and High speeds.Someone along the way,as I am the 3rd owner,re-set the fan's to come on primary 184 and secondary 195 without changing the stock 180F Thermostat.The Fan's have been running forever all the time. I suspect it's the Fan Motor? Am I on the right track as I changed all 3 Relay's.Could it be a PCM Issue? The Right side comes on High when I turn on the A/C.
I stopped and opened the hood and sure enough, the Left Fan was not running. This morning I checked it and the same thing ,No Left Fan.Right side is running on Low and High speeds.Someone along the way,as I am the 3rd owner,re-set the fan's to come on primary 184 and secondary 195 without changing the stock 180F Thermostat.The Fan's have been running forever all the time. I suspect it's the Fan Motor? Am I on the right track as I changed all 3 Relay's.Could it be a PCM Issue? The Right side comes on High when I turn on the A/C.
It uses three relays to allow the fans to run in series for low and parallel for high. What you describe sounds like the fan motor.
You probably bought three relays you didn't need.
The fans do not usually run at highway speed. They were reprogrammed a bit low but that will only apply at speeds below approximately 45 MPH.
Racer
Joined: Sep 2008
Posts: 456
Likes: 0
From: FL
Diagnose problem first then replace parts. Even if you accidentally replaced bad part it is still stupid way to solve problem. Get a manual, read diagram, check voltage with tester. Tester cost 10 doll and digital one 16. Get it.
Check resistance on fan terminals, it should be about 1-2 Oms. Apply voltage to fan to see if it works.
First find out how fan is supposed to work. It is possible than fans don't work together. Computer turns on one fan let us say at 210, another one at 220.
Engines work at temp above water boiling point (213). I would say 220 is normal temp. So find manual.
Check resistance on fan terminals, it should be about 1-2 Oms. Apply voltage to fan to see if it works.
First find out how fan is supposed to work. It is possible than fans don't work together. Computer turns on one fan let us say at 210, another one at 220.
Engines work at temp above water boiling point (213). I would say 220 is normal temp. So find manual.
Melting Slicks
Joined: Feb 2008
Posts: 3,286
Likes: 6
From: Palm Beach
Just looked at my 96 FSM. I don't see anything about taking the fans out from the bottom. It does say to raise the car to remove the skid bar. I would think that is to gain access to something. The fans should come out the top.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
There is no fan thermostat. The fans are controlled by the PCM with info from the coolant temp sensor in the waterpump.
It uses three relays to allow the fans to run in series for low and parallel for high. What you describe sounds like the fan motor.
You probably bought three relays you didn't need.
The fans do not usually run at highway speed. They were reprogrammed a bit low but that will only apply at speeds below approximately 45 MPH.
It uses three relays to allow the fans to run in series for low and parallel for high. What you describe sounds like the fan motor.
You probably bought three relays you didn't need.
The fans do not usually run at highway speed. They were reprogrammed a bit low but that will only apply at speeds below approximately 45 MPH.
Theory of operation correct.Diagnose problem first then replace parts. Even if you accidentally replaced bad part it is still stupid way to solve problem. Get a manual, read diagram, check voltage with tester. Tester cost 10 doll and digital one 16. Get it.
Check resistance on fan terminals, it should be about 1-2 Oms. Apply voltage to fan to see if it works.
First find out how fan is supposed to work. It is possible than fans don't work together. Computer turns on one fan let us say at 210, another one at 220.
Engines work at temp above water boiling point (213). I would say 220 is normal temp. So find manual.
Check resistance on fan terminals, it should be about 1-2 Oms. Apply voltage to fan to see if it works.
First find out how fan is supposed to work. It is possible than fans don't work together. Computer turns on one fan let us say at 210, another one at 220.
Engines work at temp above water boiling point (213). I would say 220 is normal temp. So find manual.
MK 82s explanation is right on. At half speed 12 volts applied to a series combination of the 2 fans so each operates at 6 volts. At high speed fan windings become a parallel configuration each operating at 12 volts.
Hence an open winding on the left fan would shutdown low speed operation (series) on the left fan. But Cajun says he has low and high speed operation on the right side fan. So if all facts are true, this leads me to believe the winding for the left fan is good but the shaft might be seized as in a bad fan bearing or internal problem.
A true test of the fan is to disconnect the left fan and externally apply 12 volts to the fan for a true and valid test. This will definitely give you a good direction whether to replace the fan or not.
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