Cooling fan revist

jmmorgan4

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Brought up this topic yesterday here: https://www.sn95forums.com/threads/cooling-fan-wiring.78471/#post-1503823

wanted to explain the situation better cause didn't really explain one of my main points of confusion. in the thread above I was talking abouit weird voltages when the harness was plugged into the fan, but when you unplug the harness it acts completley differently. when its unplugged the wires energize seperatley around 12 to 14 volts whenever the computer calls for its repected hi or lo wire to be energized. so does that mean when i plug it into the fan they gain continuity? they both go to the same motor so it makes sense but what little I know about eletrcity when you connect two differnt voltages together they equlize. Not sure whats happenig here, but maybe I'm just a noob when it comes to eletric motors
 
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jmmorgan4

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Does your fan work? I’m kind of confused what your issue is.
yes the fan works but i added indicator lights on the interior to tell when the hi and lo fan are on but both lights just come on together since somehow both fan wires are connected. going to replace the radiator and maybe fan so wanted to understand the wiring to see if i could reuse it versus running a new fan cotroller harness
 

07GtS197

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yes the fan works but i added indicator lights on the interior to tell when the hi and lo fan are on but both lights just come on together since somehow both fan wires are connected. going to replace the radiator and maybe fan so wanted to understand the wiring to see if i could reuse it versus running a new fan cotroller harness
If the wiring is ok and not burnt you shouldn’t need a new harness.
 

joemomma

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I don't have much insight to add here, but to help other forum members out, please don't start a new thread for the same issue. It makes it easier for everyone to have all the info in one thread.
 

ttocs

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Brought up this topic yesterday here: https://www.sn95forums.com/threads/cooling-fan-wiring.78471/#post-1503823

wanted to explain the situation better cause didn't really explain one of my main points of confusion. in the thread above I was talking abouit weird voltages when the harness was plugged into the fan, but when you unplug the harness it acts completley differently. when its unplugged the wires energize seperatley around 12 to 14 volts whenever the computer calls for its repected hi or lo wire to be energized. so does that mean when i plug it into the fan they gain continuity? they both go to the same motor so it makes sense but what little I know about eletrcity when you connect two differnt voltages together they equlize. Not sure whats happenig here, but maybe I'm just a noob when it comes to eletric motors
I am not sure what you mean by "gain continuity". Never heard those two put together before.

yes the fan works but i added indicator lights on the interior to tell when the hi and lo fan are on but both lights just come on together since somehow both fan wires are connected. going to replace the radiator and maybe fan so wanted to understand the wiring to see if i could reuse it versus running a new fan cotroller harness
How did you add the lights? What kind of lights (led/halogen)?

Its been for ever since I looked at the stock fan but if I remember correctly both wires are energizes when it is on high speed. There are two different motor windings that they go to on the same fan blade and with both energized it spins faster. I thought they were both supposed to go to 12v though.

Have you looked at the schematic for the circuit with the fan motor in it? I have not looked at it for a couple of years and probably need to in order to give the best advice here. I will see if I remember can dig out my oem electronics manual later.
 
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jmmorgan4

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I am not sure what you mean by "gain continuity". Never heard those two put together before.


How did you add the lights? What kind of lights (led/halogen)?

Its been for ever since I looked at the stock fan but if I remember correctly both wires are energizes when it is on high speed. There are two different motor windings that they go to on the same fan blade and with both energized it spins faster. I thought they were both supposed to go to 12v though.

Have you looked at the schematic for the circuit with the fan motor in it? I have not looked at it for a couple of years and probably need to in order to give the best advice here. I will see if I remember can dig out my oem electronics manual later.
when the harness is unplugged the lo fan and hi fan wires don’t have continuity theyre just two completely separate wires. when i plug the harness into the fan the all of sudden have continuity so somehow they’re being connected through the motor.

i just tapped into the wires to add the light and they are led. i figured both wires would energize when the fan is on high but when it’s on low they both are energized as well just at lower voltages than when they’re on the hi setting
 

cobrajeff96

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Better than adding LEDs on the output wires leading to the fan is to add them to the inputs that trigger the relays in the CCRM (low current draw). You've got a huge inductive load on those output wires leading to the fan motor and over time your LEDs will get weird or fail. It's just too much current (around 70A on high speed).

Just a guess but the fan motor will have windings, essentially like an alternator in order to spin the stator around. That lower voltage you read may just be bleed over from the 'primary' winding of the low speed or whichever it was when you first posted. Like I said, probably nothing.

Now, however, if the fan bearing is having issues and is ready to give up the ghost, there is a chance it's dragging and essentially creating extra resistance and more power is required to spin it, and more of a voltage drop will be reported by your multimeter. But you'd likely hear such a problem and even smell it if it's bad enough. And this is probably where your cooking fan motor electrical harness would come into play that we've seen happen to people over the years. Again, maybe.

But if you suspect anything and you're sure it's not the fan motor itself, suspect the CCRM first is my piece of advice. It's unlikely you have a short to ground on any of the hot wires in any part of the system because fuses would blow and you'd get no fan at all.

Attached some items of interest for you...
 

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  • CCRM Connector Pic & Pinout.JPG
    CCRM Connector Pic & Pinout.JPG
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ttocs

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when the harness is unplugged the lo fan and hi fan wires don’t have continuity theyre just two completely separate wires. when i plug the harness into the fan the all of sudden have continuity so somehow they’re being connected through the motor.

i just tapped into the wires to add the light and they are led. i figured both wires would energize when the fan is on high but when it’s on low they both are energized as well just at lower voltages than when they’re on the hi setting
I see what you mean now. My confusion is that no circuit has continuity till it is completed

Have you heard about how if you put leds in your parking lights that they flash really fast? That is because they change the impedance of the circuit and cause the flasher to go so fast. As he said I am not sure that they are the best idea here.

ccrm's have been failing more and more over the years.
 

cobrajeff96

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A couple of pointers to add...

When testing for continuity on the positive side of a circuit, do it with power locked out (either pulling the fuse or removing the negative battery cable). Not doing so could damage the multimeter.

You can test for continuity on a ground path at any time.

An LED draws very little current and you won't be changing the resistance of a circuit hardly at all (impedance only exists in an AC circuit, BTW, and that term isn't applicable in an automobile). But like I said, if you put an LED on a line that's seeing huge and suddent spikes in amperage (like a fan motor), I wouldn't think the LEDs would be long for this world.
 

dcm0123

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I believe the cooling fan is a permanent magnet motor but I can not confirm it.

When a permanent magnet motor spins, it will produce electricity even if no power is connected (acting as a generator).
When you put power on one winding (hi or low speed) causing the motor to spin, there will be a voltage coming from the other winding. This is why both LED's will be lit even if power is only applied to one winding.

The main problem with the CCRM module is the cooling fan relay contacts overheat then fail to put out power. You can not easily monitor if there is power coming out of the relay. You can monitor the source which pulls in the relay which will not tell you if the contacts failed.

 
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