Cooling Fan Questions/Issues
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
Cooling Fan Questions/Issues
Car is running about 20* warmer than normal in city driving..
So I hooked up my scanner and found NO DTC s..
I commanded the FAN 1 ON - - - both come on low speed.
Then Command FAN 2 ON -- Right fan on high, left fan NO GO
ON the Fan 2 setting, are they both supposed to come on high speed??
IF so, then do i have bad fan motor OR is there a relay that
commands left side fan high operation ??
IF I put in new fans, IS just the oem replacement set up ok or should I look for better option.. Have never had cooling issues ever in 109K miles. And I am mostly stock too.
So I hooked up my scanner and found NO DTC s..
I commanded the FAN 1 ON - - - both come on low speed.
Then Command FAN 2 ON -- Right fan on high, left fan NO GO
ON the Fan 2 setting, are they both supposed to come on high speed??
IF so, then do i have bad fan motor OR is there a relay that
commands left side fan high operation ??
IF I put in new fans, IS just the oem replacement set up ok or should I look for better option.. Have never had cooling issues ever in 109K miles. And I am mostly stock too.
Team Owner
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Pilot of Beer Force 1
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I believe in the Beer Fairy
in response to keeping stock or upgrading ( if it turns out you need a new one)....IMO....no reason to upgrade fans being mostly stock living in KS.
that being said when we needed to replace the wife's fans hindsight says we should have went with the Dewitts SPAL being as she sits in traffic somedays here in FLA
that being said when we needed to replace the wife's fans hindsight says we should have went with the Dewitts SPAL being as she sits in traffic somedays here in FLA
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
If both fans come on at low speed then the problem is NOT the fan motors. It is a relay or fuse issue. Fans are wired in series electrically for low speed operation. That puts about 6 volts across each fan motor so they spin at lower than rated speed.
Fans in high speed mode are switched to be in parallel electrically so that each fan has 12 volts across it and they spin at rated (high) speed.
Here is an electrical diagram for the fans:
Given your description above of what happens on high speed I would be looking at relay 44 and fuse 14
Fans in high speed mode are switched to be in parallel electrically so that each fan has 12 volts across it and they spin at rated (high) speed.
Here is an electrical diagram for the fans:
Given your description above of what happens on high speed I would be looking at relay 44 and fuse 14
Thank You So Much. I figured maybe the left side fan motor had prob just went bad.. I will check relay 44 and fuse 14. Thanks !!!!!!
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
Still have problem.. NO HIGH SPEED on left fan.
Replaced relay 44. check fuses, mini, maxi etc
Switch around relays 43 and 45 .....
Pulled both side ground "block" things apart and cleaned everything. Checked wiring at left fan, etc etc
I just can't understand why the Left Fan would work on low just fine and not at all on high speed if it really is just a difference of the amount of voltage going to it.
HELP !!!
Replaced relay 44. check fuses, mini, maxi etc
Switch around relays 43 and 45 .....
Pulled both side ground "block" things apart and cleaned everything. Checked wiring at left fan, etc etc
I just can't understand why the Left Fan would work on low just fine and not at all on high speed if it really is just a difference of the amount of voltage going to it.
HELP !!!
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
Yes, Left = Driver's Side
It does run on low speed for sure... both do
but when I command "FAN 2" thru my Scanner, ONLY the RIGHT SIDE FAN
comes on HIGH. Left one is OFF for sure.
I would think if motor on left is bad, it wouldn't work on any speed...
I dont really care if I have to replace fans or whatever to fix the problem,
i just want it working properly.
Thanks in Advance. I am puzzled at this one
It does run on low speed for sure... both do
but when I command "FAN 2" thru my Scanner, ONLY the RIGHT SIDE FAN
comes on HIGH. Left one is OFF for sure.
I would think if motor on left is bad, it wouldn't work on any speed...
I dont really care if I have to replace fans or whatever to fix the problem,
i just want it working properly.
Thanks in Advance. I am puzzled at this one
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
Just want to clarify.. I put in NEW relay in #44. switched the 43 and 45 with NO
CHANGE when switched. So I guess they could both be bad... but no one had it
stock today.
This is really weird. Is there another ground to look for maybe ??
CHANGE when switched. So I guess they could both be bad... but no one had it
stock today.
This is really weird. Is there another ground to look for maybe ??
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
Yes KEY ON .. Commanding them thru scanners test mode for Fan 1 and Fan 2.
I will check voltage with meter. I know all the fuses are good (checked them for continuity and by eye as well.)
I will check voltage with meter. I know all the fuses are good (checked them for continuity and by eye as well.)
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Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
SO< here is my update... NO Success yet
I took off wiring at left fan.. Blue and grey wires
ON Fan 1 I get 6. volts
ON Fan 2 I get Zero Volts
I get no volts either way with it just unplugged and meter the two ends...
IT has to be plugged in to get any action. I stripped the 2 wires down and had
the wife use the scanner to command fan 1 and 2..
So no power to left fan on HIGH.. I pulled back harness and tape to see
if i could see any obvious damage- none found.
I have Brand New Relays at ALL 3 locations AND
12. volts at both maxi fuses and 14 minifuse on both sides when fans commanded on.
ANY OTHER SUGGESTIONS ????
I took off wiring at left fan.. Blue and grey wires
ON Fan 1 I get 6. volts
ON Fan 2 I get Zero Volts
I get no volts either way with it just unplugged and meter the two ends...
IT has to be plugged in to get any action. I stripped the 2 wires down and had
the wife use the scanner to command fan 1 and 2..
So no power to left fan on HIGH.. I pulled back harness and tape to see
if i could see any obvious damage- none found.
I have Brand New Relays at ALL 3 locations AND
12. volts at both maxi fuses and 14 minifuse on both sides when fans commanded on.
ANY OTHER SUGGESTIONS ????
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
I am getting frustrated at this issue...
HOW do I know which terminal of the 5 prong relay is the A11 ???
And do I just pull it with key on and check its resistance value to known
good ground ?? Or do I need to build something to check it while commanding
fan 2 on ?
HOW do I know which terminal of the 5 prong relay is the A11 ???
And do I just pull it with key on and check its resistance value to known
good ground ?? Or do I need to build something to check it while commanding
fan 2 on ?
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
The only thing that makes sense is your losing your ground signal from the PCM to relay 45 terminal E2. E2 is terminal F1 at the under hood fuse box. Command the the fans to high and check that wire for ground. If it's missing, ground it and the left fan will run on high.
If so, there is either a problem with the way your scanner is commanding the PCM or the PCM is bad. Try the test with another scanner or run the engine until it's hot enough for high speed operation and see if the left fan stops.
You could also get another ect sensor and plug it in. Turn the key on, monitor the coolant temp reading and warm the sensor with a heat gun until it's hot enough for the fans to run on high.
If so, there is either a problem with the way your scanner is commanding the PCM or the PCM is bad. Try the test with another scanner or run the engine until it's hot enough for high speed operation and see if the left fan stops.
You could also get another ect sensor and plug it in. Turn the key on, monitor the coolant temp reading and warm the sensor with a heat gun until it's hot enough for the fans to run on high.
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
The only thing that makes sense is your losing your ground signal from the PCM to relay 45 terminal E2. E2 is terminal F1 at the under hood fuse box. Command the the fans to high and check that wire for ground. If it's missing, ground it and the left fan will run on high.
If so, there is either a problem with the way your scanner is commanding the PCM or the PCM is bad. Try the test with another scanner or run the engine until it's hot enough for high speed operation and see if the left fan stops.
You could also get another ect sensor and plug it in. Turn the key on, monitor the coolant temp reading and warm the sensor with a heat gun until it's hot enough for the fans to run on high.
If so, there is either a problem with the way your scanner is commanding the PCM or the PCM is bad. Try the test with another scanner or run the engine until it's hot enough for high speed operation and see if the left fan stops.
You could also get another ect sensor and plug it in. Turn the key on, monitor the coolant temp reading and warm the sensor with a heat gun until it's hot enough for the fans to run on high.
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
The factory relays have a diagram on the side of the relay. The terminals 87A and 30 are the normal position of the relay and correspond to B11 and C10 respectively. Terminal 87 corresponds to A11.
On the bottom of the relay the terminals are labeled so you can hold the relay over the socket and identify the slots in the sockets.
You should be able to use the ohm meter function to test from pin slot 87 to ground. If there is no continuity then you need to chase wires to find the break. That may be more difficult since all you have is wire color to go by from the diagram above.
If there is no continuity to ground I would probably start by lifting the battery out, remove the battery tray and look for battery acid damage. Unless you had rodents that got in and chewed wires, the break is the path is likely to have been caused by something that is traceable such as acid damage or physical damage to wires. It is going to require some detective work on your part.
On the bottom of the relay the terminals are labeled so you can hold the relay over the socket and identify the slots in the sockets.
You should be able to use the ohm meter function to test from pin slot 87 to ground. If there is no continuity then you need to chase wires to find the break. That may be more difficult since all you have is wire color to go by from the diagram above.
If there is no continuity to ground I would probably start by lifting the battery out, remove the battery tray and look for battery acid damage. Unless you had rodents that got in and chewed wires, the break is the path is likely to have been caused by something that is traceable such as acid damage or physical damage to wires. It is going to require some detective work on your part.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
The only thing that makes sense is your losing your ground signal from the PCM to relay 45 terminal E2. E2 is terminal F1 at the under hood fuse box. Command the the fans to high and check that wire for ground. If it's missing, ground it and the left fan will run on high.
If so, there is either a problem with the way your scanner is commanding the PCM or the PCM is bad. Try the test with another scanner or run the engine until it's hot enough for high speed operation and see if the left fan stops.
You could also get another ect sensor and plug it in. Turn the key on, monitor the coolant temp reading and warm the sensor with a heat gun until it's hot enough for the fans to run on high.
If so, there is either a problem with the way your scanner is commanding the PCM or the PCM is bad. Try the test with another scanner or run the engine until it's hot enough for high speed operation and see if the left fan stops.
You could also get another ect sensor and plug it in. Turn the key on, monitor the coolant temp reading and warm the sensor with a heat gun until it's hot enough for the fans to run on high.
There are about 3 possibilities all related to relay 44.
1. The relay coil is not being energized due to loss of ign power on C11 or the PCM ground signal on A10. Relay 43 is working so both the ign power and PCM ground are reaching it meaning this failure would have to be a break in the connection just to relay 44.
2. The normally open contact is bad. The relay was replaced so this is not likely to be the failure.
3. The ground at A11 is bad. With the symptoms, this is the most likely failure.
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
No, that is not the problem. The PCM turns-on relay 45 to run the fans in low speed and the low speed is working.
There are about 3 possibilities all related to relay 44.
1. The relay coil is not being energized due to loss of ign power on C11 or the PCM ground signal on A10. Relay 43 is working so both the ign power and PCM ground are reaching it meaning this failure would have to be a break in the connection just to relay 44.
2. The normally open contact is bad. The relay was replaced so this is not likely to be the failure.
3. The ground at A11 is bad. With the symptoms, this is the most likely failure.
There are about 3 possibilities all related to relay 44.
1. The relay coil is not being energized due to loss of ign power on C11 or the PCM ground signal on A10. Relay 43 is working so both the ign power and PCM ground are reaching it meaning this failure would have to be a break in the connection just to relay 44.
2. The normally open contact is bad. The relay was replaced so this is not likely to be the failure.
3. The ground at A11 is bad. With the symptoms, this is the most likely failure.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
I already thought about it and it still makes no sense. Low fan commands the low output and high fan commands both outputs. What you are suggesting is that the PCM programming somehow got corrupted just enough to mess with the fan logic, which would be rather unlikely considering there are checks in the software against such things.