Can't find after market Secondary Fan Switch
08-15-2017, 10:24 PM
#1
Racer
Thread Starter
Can't find after market Secondary Fan Switch
Note:
I should have used the word auxillary not secondary fan or 2nd fan. The auxillary fan is located in front of the condenser and is an aftermarket fan set-up with a switch somewhere in the cabin which I can't find according to the seller.
It looks like from the few responses and lack of responses that the only way to find the switch is to trace it back from the auxiliary fan to the firewall to underneath the dash.
Now continue with original post:
Purchased a 91 Coupe. Owner lived in Colorado and never used the secondary fan someone previously installed. Car runs too close to max mark on temp gaug1e after about 20 minutes in St. Louis(it's hot here!)
I turn on the air then and everything normalizes.
He just told me he thought the switch was under the dash somewhere but he wasn't sure. I can't find the switch in the cabin even though the 2nd fan is actually installed. He said it has the second fan sensor in the left head to kind of turn the fans on before the computer calls for it. The secondary fan is installed in front of the condensor. In theory when it starts to get hot just flip the switch to add airflow.
As dumb of a question it is where are the most likely places an after market fan switch would be installed?
I know I could try tracing the wires from the fan back to the firewall but even that doesn't say here is where the switch is.
There must be some common places these type switches go and what they look like.
If this question is too much you can call me dumbo, but just don't call me late to dinner...
I should have used the word auxillary not secondary fan or 2nd fan. The auxillary fan is located in front of the condenser and is an aftermarket fan set-up with a switch somewhere in the cabin which I can't find according to the seller.
It looks like from the few responses and lack of responses that the only way to find the switch is to trace it back from the auxiliary fan to the firewall to underneath the dash.
Now continue with original post:
Purchased a 91 Coupe. Owner lived in Colorado and never used the secondary fan someone previously installed. Car runs too close to max mark on temp gaug1e after about 20 minutes in St. Louis(it's hot here!)
I turn on the air then and everything normalizes.
He just told me he thought the switch was under the dash somewhere but he wasn't sure. I can't find the switch in the cabin even though the 2nd fan is actually installed. He said it has the second fan sensor in the left head to kind of turn the fans on before the computer calls for it. The secondary fan is installed in front of the condensor. In theory when it starts to get hot just flip the switch to add airflow.
As dumb of a question it is where are the most likely places an after market fan switch would be installed?
I know I could try tracing the wires from the fan back to the firewall but even that doesn't say here is where the switch is.
There must be some common places these type switches go and what they look like.
If this question is too much you can call me dumbo, but just don't call me late to dinner...
Last edited by koritz123; 08-16-2017 at 03:52 AM.
08-15-2017, 10:33 PM
#2
I believe you need to confirm very likely that you know how the "pair" operates, if they are ..........................
Maybe you start with checking and confirming ECT/CTS sender for the ECM. Does the car have C68 (AUTO AC)?
'91 fan 1 should turn on @ 226° or AC request, 2d fan @ 235° and specific speeds or with AC request.
Did you happen to get an FSM with the purchase?
Last edited by WVZR-1; 08-16-2017 at 04:35 AM.
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koritz123 (08-15-2017)
08-15-2017, 11:17 PM
#3
Racer
Thread Starter
'91 would have a "pair" of fans stock! The second fan isn't an ADD!
I believe you need to confirm very likely that you know how the "pair" operates, if they are ..........................
Maybe you start with checking and confirming ECT/CTS sender for the ECM. Does the car have C68 (AUTO AC)?
'91 fan 1 should turn on @ 226° or AC request, 2d fan @ 235° and specific speeds or with AC request.
Did you happen to get an SM with the purchase?
I believe you need to confirm very likely that you know how the "pair" operates, if they are ..........................
Maybe you start with checking and confirming ECT/CTS sender for the ECM. Does the car have C68 (AUTO AC)?
'91 fan 1 should turn on @ 226° or AC request, 2d fan @ 235° and specific speeds or with AC request.
Did you happen to get an SM with the purchase?
Second, it has AUTO AC Climate control of course but I don't know what C68 (AUTO AC) is.
I can look these items up to find out what they are.
(I should have used the word auxillary not secondary.)
He says look at the front of the condenser and there is an auxillary
fan installed it's an aftermarket set-up.
Respectfully, if he says it has an aftermarket auxillary fan in front of the condenser then he should know. He is a dealership mechanic of many years and has taken the drivetrain out of this car and apart and put it back together with new seals and gaskets and valve parts.
Last edited by koritz123; 08-15-2017 at 11:48 PM.
08-16-2017, 01:58 AM
#4
Melting Slicks
First, don't know what an SM is.
Second, it has AUTO AC Climate control of course but I don't know what C68 (AUTO AC) is.
I can look these items up to find out what they are.
(I should have used the word auxillary not secondary.)
He says look at the front of the condenser and there is an auxillary
fan installed it's an aftermarket set-up.
Respectfully, if he says it has an aftermarket auxillary fan in front of the condenser then he should know. He is a dealership mechanic of many years and has taken the drivetrain out of this car and apart and put it back together with new seals and gaskets and valve parts.
Second, it has AUTO AC Climate control of course but I don't know what C68 (AUTO AC) is.
I can look these items up to find out what they are.
(I should have used the word auxillary not secondary.)
He says look at the front of the condenser and there is an auxillary
fan installed it's an aftermarket set-up.
Respectfully, if he says it has an aftermarket auxillary fan in front of the condenser then he should know. He is a dealership mechanic of many years and has taken the drivetrain out of this car and apart and put it back together with new seals and gaskets and valve parts.
08-16-2017, 04:37 AM
#5
Corrected SM to FSM (Factory Service Manual)
You've had "eyes on"? Have you looked for the switch/sensor that's said to be in the LH cylinder head? It would be between cylinder #1 and #3. I'd think an easy visual.
Since you have the AUTO AC I'd suggest looking into how to use the AC control to actually check the engine coolant temperature that the ECM sees from the ECT/CTS and compare that to what you're seeing on the "analog" cluster gauge. They're known to be very erratic and not to be relied upon for factual coolant temps.
I see an old post where you mention buying the FSM from a dealer - did you ever get it? If you did check 1C1-3 thru 1C1-5 for instructions for use of AC control to check various parameters of your engine.
For now I'd be concerned with the FACTORY FAN OPERATION and the "factual" engine coolant temps.
(I should have used the word auxillary not secondary.)
He says look at the front of the condenser and there is an auxillary
fan installed it's an aftermarket set-up.
Respectfully, if he says it has an aftermarket auxillary fan in front of the condenser then he should know.
He says look at the front of the condenser and there is an auxillary
fan installed it's an aftermarket set-up.
Respectfully, if he says it has an aftermarket auxillary fan in front of the condenser then he should know.
Since you have the AUTO AC I'd suggest looking into how to use the AC control to actually check the engine coolant temperature that the ECM sees from the ECT/CTS and compare that to what you're seeing on the "analog" cluster gauge. They're known to be very erratic and not to be relied upon for factual coolant temps.
I see an old post where you mention buying the FSM from a dealer - did you ever get it? If you did check 1C1-3 thru 1C1-5 for instructions for use of AC control to check various parameters of your engine.
For now I'd be concerned with the FACTORY FAN OPERATION and the "factual" engine coolant temps.
Last edited by WVZR-1; 08-16-2017 at 05:26 AM.
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koritz123 (08-17-2017)
08-16-2017, 02:18 PM
#6
Racer
any normal thinking person would put the switch within reach or the driver. my fan override is just above my right knee. PO labeled switch, and it has a yellow bulb to let you know the fan is "on". However,does not seem to do any good as far as reducing temps. having new radiator and 2 temp senders installed today, i hope for the best.
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koritz123 (08-17-2017)
08-16-2017, 02:38 PM
#7
Racer
Thread Starter
Corrected SM to FSM (Factory Service Manual)
You've had "eyes on"? Have you looked for the switch/sensor that's said to be in the LH cylinder head? It would be between cylinder #1 and #3. I'd think an easy visual.
Since you have the AUTO AC I'd suggest looking into how to use the AC control to actually check the engine coolant temperature that the ECM sees from the ECT/CTS and compare that to what you're seeing on the "analog" cluster gauge. They're known to be very erratic and not to be relied upon for factual coolant temps.
I see an old post where you mention buying the FSM from a dealer - did you ever get it? If you did check 1C1-3 thru 1C1-5 for instructions for use of AC control to check various parameters of your engine.
For now I'd be concerned with the FACTORY FAN OPERATION and the "factual" engine coolant temps.
You've had "eyes on"? Have you looked for the switch/sensor that's said to be in the LH cylinder head? It would be between cylinder #1 and #3. I'd think an easy visual.
Since you have the AUTO AC I'd suggest looking into how to use the AC control to actually check the engine coolant temperature that the ECM sees from the ECT/CTS and compare that to what you're seeing on the "analog" cluster gauge. They're known to be very erratic and not to be relied upon for factual coolant temps.
I see an old post where you mention buying the FSM from a dealer - did you ever get it? If you did check 1C1-3 thru 1C1-5 for instructions for use of AC control to check various parameters of your engine.
For now I'd be concerned with the FACTORY FAN OPERATION and the "factual" engine coolant temps.
Yes I have the FSM.
Here are pictures from today's look at the left and right sides of the engine its high-definition so you should be able to see any kind of wiring from the fan going into the engine. As far as eyes on I'm not sure where to look for the condenser I got under the car and all I see is this trash screen guard and I can't see anything behind it except what it looks like fins from a condenser but I can't see very well through the screen guard if I'm supposed to look someplace else for the condenser I'm not sure where to look.
Last edited by koritz123; 08-16-2017 at 02:41 PM.
08-16-2017, 03:00 PM
#8
Racer
Thread Starter
Corrected SM to FSM (Factory Service Manual)
You've had "eyes on"? Have you looked for the switch/sensor that's said to be in the LH cylinder head? It would be between cylinder #1 and #3. I'd think an easy visual.
Since you have the AUTO AC I'd suggest looking into how to use the AC control to actually check the engine coolant temperature that the ECM sees from the ECT/CTS and compare that to what you're seeing on the "analog" cluster gauge. They're known to be very erratic and not to be relied upon for factual coolant temps.
I see an old post where you mention buying the FSM from a dealer - did you ever get it? If you did check 1C1-3 thru 1C1-5 for instructions for use of AC control to check various parameters of your engine.
For now I'd be concerned with the FACTORY FAN OPERATION and the "factual" engine coolant temps.
You've had "eyes on"? Have you looked for the switch/sensor that's said to be in the LH cylinder head? It would be between cylinder #1 and #3. I'd think an easy visual.
Since you have the AUTO AC I'd suggest looking into how to use the AC control to actually check the engine coolant temperature that the ECM sees from the ECT/CTS and compare that to what you're seeing on the "analog" cluster gauge. They're known to be very erratic and not to be relied upon for factual coolant temps.
I see an old post where you mention buying the FSM from a dealer - did you ever get it? If you did check 1C1-3 thru 1C1-5 for instructions for use of AC control to check various parameters of your engine.
For now I'd be concerned with the FACTORY FAN OPERATION and the "factual" engine coolant temps.
08-16-2017, 07:30 PM
#9
The 90-96 cars do not need a helper fan in front of the radiator stack assembly. It is just in needed junk.
If you had turned your service manual to the page suggested by WV, you would see that you are able to get an accurate "digital" temp read out. The one in the gauge cluster is not linear, and should only be used as a rough guide.
If you had turned your service manual to the page suggested by WV, you would see that you are able to get an accurate "digital" temp read out. The one in the gauge cluster is not linear, and should only be used as a rough guide.
Last edited by ChumpVette; 08-16-2017 at 07:32 PM.
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koritz123 (08-17-2017)
08-16-2017, 10:31 PM
#10
Racer
Thread Starter
The 90-96 cars do not need a helper fan in front of the radiator stack assembly. It is just in needed junk.
If you had turned your service manual to the page suggested by WV, you would see that you are able to get an accurate "digital" temp read out. The one in the gauge cluster is not linear, and should only be used as a rough guide.
If you had turned your service manual to the page suggested by WV, you would see that you are able to get an accurate "digital" temp read out. The one in the gauge cluster is not linear, and should only be used as a rough guide.
According to the member above the 91 doesn't have any digital readout at all for engine temperature.
I have the mechanic who fixed the cruise control and the switches on the clutch and brake pedals for the cruise control and the power seats and the play in the steering column look under the dashboard and he can't find anything. Again there's no eyes on yet for this fan that is supposedly there. I've no idea why the guy would make it up though but we can't find any thing as far as the condenser goes cuz I can't see through the trash grill.It's on the front of the condenser under the car.
Maybe the answer is to get a add-on temperature gauge if there's somewhere to put a sensor on the engine block, already he has an add-on oil temperature gauge and I wonder if I could use that and just disconnect it from the sensor on the engine and then put it on another sensor for engine temperature.
Last edited by koritz123; 08-16-2017 at 10:36 PM.
08-17-2017, 04:14 AM
#11
Open your book to the page that WVZR-1 mentioned. The Service Manual is your best friend.
As long as you have electric climate control (C68) option, you can get the digital readout. Hold the fan speed up & down buttons down for 5-10 seconds. It will then come up with 00 scroll through until you reach 16 and press the auto fan speed button. You will get the temp in Centigrade.
If you have manual AC (C60) you will be needing a scan tool to show the coolant temp.
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koritz123 (08-17-2017)
08-17-2017, 08:35 AM
#12
Melting Slicks
Member Since: Sep 2008
Location: Cherokee National Forest TN
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Inside the center console & the glove box are favorites to hide a switch maybe look there.
Have work clothes & a flash light? Your going to need them owning a C4, should have been a factory option with an RPO#.
Have work clothes & a flash light? Your going to need them owning a C4, should have been a factory option with an RPO#.
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koritz123 (08-17-2017)
08-17-2017, 05:05 PM
#13
Racer
Thread Starter
He is wrong.
Open your book to the page that WVZR-1 mentioned. The Service Manual is your best friend.
As long as you have electric climate control (C68) option, you can get the digital readout. Hold the fan speed up & down buttons down for 5-10 seconds. It will then come up with 00 scroll through until you reach 16 and press the auto fan speed button. You will get the temp in Centigrade.
If you have manual AC (C60) you will be needing a scan tool to show the coolant temp.
Open your book to the page that WVZR-1 mentioned. The Service Manual is your best friend.
As long as you have electric climate control (C68) option, you can get the digital readout. Hold the fan speed up & down buttons down for 5-10 seconds. It will then come up with 00 scroll through until you reach 16 and press the auto fan speed button. You will get the temp in Centigrade.
If you have manual AC (C60) you will be needing a scan tool to show the coolant temp.
So coolant temperature is the best way to check engine temperature?
Last edited by koritz123; 08-17-2017 at 05:18 PM.
08-17-2017, 07:28 PM
#14
Racer
Thread Starter
He is wrong.
Open your book to the page that WVZR-1 mentioned. The Service Manual is your best friend.
As long as you have electric climate control (C68) option, you can get the digital readout. Hold the fan speed up & down buttons down for 5-10 seconds. It will then come up with 00 scroll through until you reach 16 and press the auto fan speed button. You will get the temp in Centigrade.
If you have manual AC (C60) you will be needing a scan tool to show the coolant temp.
Open your book to the page that WVZR-1 mentioned. The Service Manual is your best friend.
As long as you have electric climate control (C68) option, you can get the digital readout. Hold the fan speed up & down buttons down for 5-10 seconds. It will then come up with 00 scroll through until you reach 16 and press the auto fan speed button. You will get the temp in Centigrade.
If you have manual AC (C60) you will be needing a scan tool to show the coolant temp.
I held the fan buttons down until the display showed - 00 and cycled up to - 16 then hit the Auto Button. The display then said 86 outside temp. So is this the Celsius reading and I convert to fahrenheit which is
186.8?
08-17-2017, 08:35 PM
#15
You might compare that number to the cluster gauge and determine how accurate your own gauge could be.
Monitor that TEMP intermittently until you're comfortable with coolant temps and maybe check the fans behind the radiator for operation. Using Celsius I'd expect fan operation for left @ 108° +/- or when AC on, right fan 113° +/-.
Regarding the PO and the aux fan switch if he did you could likely reach and feel the switch he added. This image is from an earlier L98 which would have that switch, using this as a guide you could search/feel.
There's a section of the FSM I'd suggest you spend some time with. That section is 8A-201-0 and beyond. That can be very useful in finding your way around your car.
Last edited by WVZR-1; 08-17-2017 at 09:00 PM.
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koritz123 (08-18-2017)
08-17-2017, 10:57 PM
#16
Racer
Thread Starter
I don't believe it said "outside temp" I'm accustomed to seeing only the CELSIUS TEMP and I believe that's all your '91 will display. Your conversion looks correct. It seems that you've mastered that.
You might compare that number to the cluster gauge and determine how accurate your own gauge could be.
Monitor that TEMP intermittently until you're comfortable with coolant temps and maybe check the fans behind the radiator for operation. Using Celsius I'd expect fan operation for left @ 108° +/- or when AC on, right fan 113° +/-.
Regarding the PO and the aux fan switch if he did you could likely reach and feel the switch he added. This image is from an earlier L98 which would have that switch, using this as a guide you could search/feel.
Attachment 48197464
There's a section of the FSM I'd suggest you spend some time with. That section is 8A-201-0 and beyond. That can be very useful in finding your way around your car.
You might compare that number to the cluster gauge and determine how accurate your own gauge could be.
Monitor that TEMP intermittently until you're comfortable with coolant temps and maybe check the fans behind the radiator for operation. Using Celsius I'd expect fan operation for left @ 108° +/- or when AC on, right fan 113° +/-.
Regarding the PO and the aux fan switch if he did you could likely reach and feel the switch he added. This image is from an earlier L98 which would have that switch, using this as a guide you could search/feel.
Attachment 48197464
There's a section of the FSM I'd suggest you spend some time with. That section is 8A-201-0 and beyond. That can be very useful in finding your way around your car.
Here are pics from the process. Mine say outside for some reason after I hit the AUTO button.
You have some helpful suggestions! I'll check for the switch on the engine tomorrow. This should all help give me some kind of feel for what temperature the engine is really running at.
Last edited by koritz123; 08-17-2017 at 11:10 PM.
08-18-2017, 01:33 AM
#17
Nope, you made a mistake.
After cycling to -16, press the center fan speed button of auto. It will then give you a 2 digit number, or 3 digit if it is really hot.
After cycling to -16, press the center fan speed button of auto. It will then give you a 2 digit number, or 3 digit if it is really hot.
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koritz123 (08-18-2017)
08-18-2017, 08:46 AM
#18
Melting Slicks
Member Since: Sep 2008
Location: Cherokee National Forest TN
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Infrared temp guns are real short $$ anymore mine cost north of 2 bills a long time ago.
Handy for checking thermostat opening temp, running temp, AC vent temp, tire & rotor temp for track cars.
Handy for checking thermostat opening temp, running temp, AC vent temp, tire & rotor temp for track cars.
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koritz123 (08-18-2017)
08-18-2017, 05:13 PM
#19
Racer
Thread Starter
Thanks, I'll try the other button after work.
Okay, it's after work now and I hit the button with the fan blade on it and it read
35 which would be 95 Fahrenheit. Man my car runs cool! And that's after a 1 minute warm-up.
Later after 25 minutes it's 102c or 215f
Last edited by koritz123; 08-18-2017 at 09:50 PM.
08-18-2017, 05:14 PM
#20
Racer
Thread Starter