After being parked the HVAC blower motor does not work

2005 INFINITI G35
102,567 MILES • 3.5L • V6 • 2WD • AUTOMATIC
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MALLYBOY
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This vehicle was parked over an extended period, but before parking it, the AC was working fine. Now the vehicle owner wants to start using the vehicle back, when he turns on AC and notice that blower was not working and he drove to my workshop and I used factory diagram to trace power and signal from A/C amplifier and also ground, it passed test, I diagnosed the A/C system, and it didn't report fault code. At this point I suspect that the A/C system is automatic not manual A/C that the blower turns on with ignition on, but automatic A/C hence there's no refrigerant in the system to pressurize and send signal to A/C Pressure sensor to turn the blower on, the blower will not work. Or is there anything else?
Jun 28, 2022 at 10:00 AM
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JACOBANDNICKOLAS
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Hi,

The blower motor will work if the A/C refrigerant is low or empty. The blower motor on this gets power from two fuses in the fuse box in the vehicle behind the left kick panel. See pic 1 below.

For the motor to operate, a ground path has to be provided by the AC amplifier.

Check fuses first. Make sure they are good and have power to and from them. If they are good. Note that they will only have power with the key on or in acc. If they are good, go to the blower motor and check the blue wire with a white tracer for power.


Let me know what you find.

Take care,

Joe

See pic below,
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Jun 28, 2022 at 8:49 PM
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MALLYBOY
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Note that they will only have power with the key on or in acc. If they are good, go to the blower motor and check the blue wire with a white tracer for power. I have traced the fuses and they are okay, then I go to the blower motor and check the blue wire with white trace while I turn the ignition to Acc and on position, but it didn't operate, I measure voltage on the blue wire it gives 12volts, I checked the resistance to ground and it was okay. Now I measure voltage on green wire from a.c. amplifier and it reads 04.57volts, I said that it is not the a.c. amplifier...it is supply power to the blower
Jun 29, 2022 at 4:33 PM
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JACOBANDNICKOLAS
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Hi,

If you have power to the blower motor and you have ground, it sounds like the motor itself has failed.

The 4.57 volts from the amplifier is lower than the battery voltage based on how fast the fan should be turning. I feel the motor needs to be replaced.

I attached the directions below. This isn't a bad one to do.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pic below.
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Jun 29, 2022 at 10:56 PM
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MALLYBOY
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I feel the motor needs to be replaced!
Removed the blower motor and tested it with battery by connecting blue/white wire to positive terminal of battery and black wire to negative battery terminal, it didn't operate, but was making some kind of small spark on battery head when connected.
I also probe the green to positive terminal and black to negative terminal, it didn't operate.
Noe, how do I test the blower motor with battery to confirm first before replacing it?
Jul 1, 2022 at 12:09 AM
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JACOBANDNICKOLAS
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Hi,

It sounds like you did it. If there was no response, it does sound like the motor itself has failed. As far as testing is concerned, when you placed the blue/white wire on battery + and grounded the black wire, the motor should have run full speed. Can you spin the motor freely or does there seem to be resistance?

If possible, let me know if the new one takes care of the issue. I suspect it will, but I would just like to confirm.

Take care,

Joe
Jul 1, 2022 at 8:26 PM
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MALLYBOY
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Thank you so far for your assistance.
I have replaced the Blower Motor and still it didn't operate. But I didn't use battery to test it because I am afraid if the Blower Motor will flash if I test it direct with battery.
Jul 7, 2022 at 3:53 AM
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JACOBANDNICKOLAS
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I'm not sure I understand. What do you mean by flash? Do you mean spark? If that is your concern, it really won't hurt anything and will be minimal when the connection is first made.

Let me know.

Joe
Jul 7, 2022 at 1:40 PM
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MALLYBOY
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I'm not sure I understand. What do you mean by flash? Do you mean spark?
When it sparks, it will damage some I.Cs on the motor panel causing it to damage.
But have you used battery to check and be sure it works like that with battery?
Jul 7, 2022 at 1:45 PM
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JACOBANDNICKOLAS
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Hi,

I have. You can use something like a jumper pack that you can turn on and off. Turn the pack off, make good connections, and then turn the pack on for a second or two.

Let me know.

Joe
Jul 7, 2022 at 4:47 PM
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MALLYBOY
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I don't know what you mean by jumper pack, send me the picture of the jumper pack let me see how it looks like and to know if I will construct something similar.
Jul 7, 2022 at 8:25 PM
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JACOBANDNICKOLAS
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Hi,

It's a power source used to jump-start a vehicle. I attached a pic below. You just need something that can supply 12v.

Joe
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Jul 7, 2022 at 9:20 PM
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MALLYBOY
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Hoooyi! Finding this kit in Nigeria is difficult. Going by using battery to test the blower motor will do the same as the kit? Because I will be going to shop where they sale blower motors, anyone that runs with battery is good.
What if I used battery and test all the blower motor in the shop and none work? and
Where is blower motor relay located?
Jul 8, 2022 at 3:39 AM
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JACOBANDNICKOLAS
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Hi,

If they don't run when you power them, that would indicate they are not good. As far as the blower relay, this vehicle doesn't have one. The motor function is controlled by the ac amplifier.

Let me know how things turn out for you.

Take care,

Joe
Jul 8, 2022 at 7:30 PM
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MALLYBOY
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If they don't run when you power them, that would indicate they are not good.
The blower motor I used for the testing was used one from another vehicle not brand new. I suspect that may be the reason why it is not working. We hardly have brand new parts here. Would you help with one let me see how we will do it?
Jul 9, 2022 at 1:06 AM
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JACOBANDNICKOLAS
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Hi,

I'm not sure what you meant. You said, "Would you help with one let me see how we will do it?" Do you need me to find one? They are easily accessible here, but I'm not sure how I would get it to you.

Let me know.

Joe
Jul 9, 2022 at 10:34 PM
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MALLYBOY
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They are easily accessible here, but I'm not sure how I would get it to you.
Okay.
I also noticed that fan1 motor was not operating only fan2 and I trace power and there was no power to it. When I get to IPDM/ER and see that water fill the panel and some ICS, this could also be the reason why blower motor not working as there's open circuit which the Av module is detecting by not operating the blower motor.
Jul 10, 2022 at 3:32 AM
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JACOBANDNICKOLAS
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Hi,

If the module was filled with water, there is a good chance it is now shorted. By any chance, do you have a working one that you could try?

Joe
Jul 10, 2022 at 7:45 PM
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MALLYBOY
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I will look for one and check and after which I will let you know.
Jul 10, 2022 at 11:51 PM
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JACOBANDNICKOLAS
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Hi,

Sounds like a plan. I will watch for your findings.

Take care,

Joe
Jul 11, 2022 at 9:29 AM
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MALLYBOY
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I got another IPDM/ER but immediately I put it and turn on ignition, Service Engine Light went off but still the blower didn't operate and fan1 motor didn't operate. I put the second the IPDM/ER the service engine didn't come on and blower and fan motor1 didn't operate.
So finally, I open the IPDM/ER that comes with the vehicle and wash it with fuel and put under the sun, when it dry, I couple it back, then the fan motor1 begin to operate, but service engine light didn't come on and blower didn't operate. I have checked all the fuses and relay but all good. Is this from the communication line?
Jul 21, 2022 at 4:51 AM
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JACOBANDNICKOLAS
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Okay, you confirmed there is power to the blower motor blue/white wire. You confirmed there is ground, and you had 4.57v from the pulse width modulator. The fan should be running.

Do me a favor. Check to see if the voltage drops when you request the fan motor on. We must have a weak connection at some point.

Let me know.

Joe
Jul 21, 2022 at 6:10 PM
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MALLYBOY
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No there is no voltage drop when I on blower motor on.
What I need now is to know why the Service Engine Light has stopped illuminating after testing another fuse box on the vehicle?
Jul 22, 2022 at 12:48 AM
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JACOBANDNICKOLAS
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If you replaced the box, you had power off to everything. I suspect you reset things. If there is no voltage drop, it sounds like the problem could be at the switch. I'm not sure what to tell you. You have power where it needs to be, the motor is good, you have ground, it should run. We have to be missing something simple. When you checked for a voltage drop, did you do it at the motor?

Joe
Jul 23, 2022 at 8:13 PM
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MALLYBOY
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Thank you once again, I have come to tell you that I replaced another used blower motor but there's something strange on tje PWM wire from A/C amplifier. When you increase the speed of blower, instead of the voltage to drop as speed is increasing, the voltage will also be increasing. When I on the blower motor, it didn't operate and I remove the PWM-wire and ground it to negative wire and the blower run at its maximum speed. I connect it back but still it didn't operate. At this point I suspect faulty AC amplifier.
Aug 4, 2022 at 2:02 PM
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JACOBANDNICKOLAS
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Hi,

I agree with your diagnosis. Also, when you increase fan speed, you are increasing voltage, so what you said sounds correct.

Let me know if the amplifier takes care of the issue.

Take care,

Joe
Aug 4, 2022 at 5:00 PM
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MALLYBOY
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Let me know if the amplifier takes care of the issue. Yes.
I replaced another A/C amplifier and the problem solved.
Aug 25, 2022 at 7:03 PM
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JACOBANDNICKOLAS
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Hi,

Thank you for the update. I had a feeling that is where the issue was coming from and I'm glad it's fixed.

Take care of yourself and feel free to come back anytime in the future.

Joe
Aug 25, 2022 at 8:06 PM