AC/Heater Blower Just Stopped Working... ADVICE PLEASE

E

ericsantiago

Member
Name
Eric
Hello Everyone.
I have an issue that started this morning on the way to work. Got into my car and turned on the AC and nothing came out. Tried the heat also. Nothing came out. After approximately 15 minutes a weak stream of cold air came through then no air again(hot or cold). Air conditioner had been working fine before today and there's been no strange noises coming from blower. Someone at work said it could be the blower relay. If that is what the problem is where is it located on my 2012 fx35 and can I change it myself?
Thanks guys
 
If it was making some noise as you described then most likely the blower needs to be replaced.
It's not a difficult job to do. I did a DIY for my 04 not sure if it's the same as the 12 but shouldn't be much different.
 
MTN FX said:
If it was making some noise as you described then most likely the blower needs to be replaced.
It's not a difficult job to do. I did a DIY for my 04 not sure if it's the same as the 12 but shouldn't be much different.
Click to expand...
No. theres been no noise whatsoever. It's always run really quiet. I could see if there was some sort of rubbing but was perfect until this morning. Hopefully its not the blower itself.
 
Oops sorry misread that thought you had some noise.
 
MTN FX said:
Oops sorry misread that thought you had some noise.
Click to expand...
NO problem. Looking at other online sources and it seems the fuse box which may contain the blower relay is behind the battery on the firewall. Did the replacement you connected have one on the blower itself? Had seen a diagram with one attached to blower unit
 
If memory serves correctly, the blower fuses are in the cabin fuse box by the parking brake pedal. They are two 15A fuses.
If the fuses are good, then check the power going to the motor. If there is power, then the motor is dead.
 
Kanedean said:
If memory serves correctly, the blower fuses are in the cabin fuse box by the parking brake pedal. They are two 15A fuses.
If the fuses are good, then check the power going to the motor. If there is power, then the motor is dead.
Click to expand...
Both fuses are toast. Bought a few new sets and the blow every time I start the car. Must be a short somewhere. Glad it's still under warranty. I hope it's nothing in the harness.
Would hate to have to leave it at the dealer for God knows how long it take to figure this out. Thanks for the guidance though. Will keep you guys posted
 
Correction - Both fuses are blowing. They are parallel wired so that 2 15 = 30 amp total.

I fixed it. I unplugged the motor and they didnt blow so I knew it was a short. I took it apart to see if it was repairable but no luck.

New part from auto zone - about 170$. I would normally buy online and save 40-50$ and get oem, but for AC - some things dont go on the waiting list. . .
 
Alright everyone, Im big into root causing so I did a tear down on my old blower so all of you could have the information on WHY it failed.

There was a short in my system as tested at the incoming ports. There are 2 components in the system, amplifier and motor. I isolated the 2 items and found the short to be on the amplifier board. (It is sold as one unit, but the amplifier can be accessed)

After teardown, I found evidence of water being let into the amplifier compartment and collecting on the boards allowing short circuit and permanent damage on the high power connections going to the motor. - So one must ask, how does water get into this area?

Amp.jpg





I havent confirmed it, but I did a search on the forum for leaks that develop on the passenger side that leak INTO the HVAC blower area. LOW and BEHOLD there is a known issue AFTER changing the battery. (I changed my battery in the last 3 months). The symptoms include a musty smell. (I had a G35 with the sun roof drain issue so im very familiar with the early symptoms of a leak).

Here is what I suspect is the root cause, My symptoms were more minor, hoever this allows water DIRECTLY into the blower motor compartment. Its a direct drip down.

QX70 09-17 - Leak in my passenger footwell This explains the water intrusion issue.

POST 14 Says the manual says you MUST change the cowl seal and NOT re use it any time the battery is changed. I can confirm with the following snip it from my manual.

RePlace Seal.PNG

Theres a probably a reason it says that.... Either way I will investigate and see if I have this leak. I imagine I do. All the symptoms are there. It would be stupid of me to allow water to continue to come in and keep replacing blower motor amps... (I will try and investigate if the amp can somehow be procured seperately... but I doubt it, I cant even find a part #)

To be CRYSTAL clear, see pic of the seal that CANNOT be re used. Number 12.
Non USable Part.PNG
 
Thanks for the links, hopefully it helps someone in the future.

I have to add that I tested for leaks and did not find any. I'll continue to monitor and come back and update of I find definitely where the water in my amplifier on the bottom of the blower motor came from.
 
Alright. Just a follow up. I've blown another blower motor and had to replace it due to water getting in.

Additionally this time.... The water also proceeded to drip out on my illumination control module and fry that also. ($400 used :/ )

I've spent hours with a water hose and can't reproduce the intrusion. I've tried parking at different angles also while water testing.

My current theory is that it happens when driving possibly to explain the lack of reproduction with a water hose. (I've been able to re produce other infiniti leaks this way)

So far it's a real head scratcher. It's pretty sorry - but when I out the replacement parts in, I'll be water proofing where the water intruded last time on the electronic module . . .

I still think the water is coming in at the fresh air intake since that's the easiest path to the blower motor. But i can't reproduce it.

I almost need a second, never leaked fx and spray them both down side by side and make sure all the water flows the same ways through the drainage process.
 
yeah possibly. Or the next time its raining good go take a drive on the highway for 20 minutes and check the area for water. Being able to identify when it happens is my first step I guess.
 
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