2003 Pathfinder - No air coming from vents

[kristin517]

Hi,

I have a 2003 Pathfinder SE, and there is practically no air coming out of the vents. It doesn't matter if the temperature is set to 60 or 80. When I put up the fan to the highest it will go nothing happens. There is a tiny bit of air coming out but it doesn't change when I increase the fan. I have been reading about a possible cause and what I've found is it's probably the blower motor. I was going to try to take out the glove box tomorrow to take a look at it, but wanted people's opinions before I did. Anyone else have this issue? Anything else it could be besides that?

Thanks,

Kristin

[AZhitman]

Welcome aboard!

A few things - Could be a plugged-up cabin filter, but more likely a shot blower motor.

Here's a big help - Go grab the FSM for your Pathy at www.nissanservicemanuals.com and check the HVAC section. It'll walk you right through the R&R of the blower motor.

[kristin517]

Awesome! Thanks for the quick reply. I will come back and let you know.

[AlanAZ]

The blower on my 2003 died ~3 years ago. And I've had clogged cabin filters, it doesn't stop it blowing air.

There is a tiny bit of air coming out but it doesn't change when I increase the fan.

If that was while you're driving, check it again when stopped.

[atraudes]

To clarify, it sounds like you're getting little if any air flow out of the vents, correct? Are you hearing the blower running at all, or is it completely silent? If it is making noise, does the noise change at all when you change the fan settings?

[kristin517]

Hi,

So, I took out the blower motor today and tested it by hooking it up to power, and it runs fine - so it is not the actual blower that's the problem.

To answer the questions above:

"If that was while you're driving, check it again when stopped." No, now that I checked when it's not moving there is absolutely no air coming out.

"To clarify, it sounds like you're getting little if any air flow out of the vents, correct? Are you hearing the blower running at all, or is it completely silent?" Now that I still have the glove box out, I can say for sure that the blower is not coming on, but I do hear something come on when I turn the heating/ac system on. It's not really that something "comes on" but more like the engine downshifts. Not sure if that's the right word, but something is turning on (the compressor?).

By answering these questions, it would seem to me that it's not getting power, but from where? I ran through some of the trouble shooting in the service manual and here is what I found:

Question: Do approx. 12 volts exist between fan control amp. harness connector terminal No. 3 and body ground? - YES, it is just under 12 Volts

Question: Does continuity exist between fan control amp. harness connector terminal No. 1 and body ground? - NO, but I am unsure if I am doing it correctly. On my meter it's just showing up as "1"

Now, for clarification, this was checking the power supply for the fan control amp. I went to this because it fits the symptom: "Blower motor operation is malfunctioning under Starting Fan Speed Control."

I was going to do the Self-diagnosis next, but I'm not sure if this is going to test anything I need to worry about being the problem. I also need to check the fuses under the hood. Could that be where the problem is?

[AZhitman]

It's not really that something "comes on" but more like the engine downshifts. Not sure if that's the right word, but something is turning on (the compressor?).

There's a solenoid that kicks up engine idle (very slightly) when the AC is turned on. That's what you're hearing.

[atraudes]

I would have a careful read through this thread. It's lengthy (sorry), but at minimum it'll give you some good starting points and things to look at and test. You've already made some excellent determinations so you're on a good track.

[kristin517]

I would have a careful read through this thread. It's lengthy (sorry), but at minimum it'll give you some good starting points and things to look at and test. You've already made some excellent determinations so you're on a good track.

Fantastic!! Replaced fan control amplifier (part # 27761-70T03) as indicated on that thread and I have air yet again.

Thank you so much for referring me there. I probably would have ended up there eventually, but reading through that thread gave me the confidence that this was most likely the issue and instead of continuing to troubleshoot I decided to give it a try.

[atraudes]

Nice! Glad to hear it!