Patherfinder Heater Blower Issue

[agrant32]

The blower works in the mornings after sitting all night no problem. But after I get to work and try to start it again after a couple of hours (I drive around a lot for work), the blower won't work the rest of the day. Once in a while it will randomly kick on once in while as I am driving down the road. Is it the amp? or resistor?

[Towncivilian]

Do you have the auto or manual A/C controls?

Welcome to NICO.

[agrant32]

Automatic

[Towncivilian]

You have a fan control amp, and no blower motor resistor. Please try running self-diagnosis described on page HA-45 of the factory service manual and report your results.

[agrant32]

Looks like 25 sunload sensor?

[Towncivilian]

Did you perform the diagnosis in direct sunlight (i.e. shining on the sunload sensor, which is the black circle on the passenger side of the dash)? If not, park in direct sunlight and try running it again.

If you get code 25 again, the diagnosis procedure for the sunload sensor is very convoluted (see HA-135) and it's probably difficult to access most of the required wiring harnesses to test. Luckily, a sunload sensor is pretty cheap ($32.72 for an OEM one online) so you may want to try replacing it. Let me do some more searching though before you order it, maybe somebody else has encountered this issue before and can share their fix.

Have you ever changed the cabin air filter?

[agrant32]

It was later in the afternoon so sunlight was scarce. I will try again in direct sunlight.

I have not changed the cabin filter.

[Towncivilian]

You may wish to change it out, if it's the original one it's almost certainly restricting airflow by now. See this thread for a guide on changing the filter.

[agrant32]

Sunload sensor is ok after doing check in sunlight. When I get to the 41-46 check, I can hear the compressor turning on and off but no air comes out. Air comes out when I am driving though.

[Towncivilian]

See this thread, the issue the OP has sounds similar to yours.

[agrant32]

I've read the suggested thread. From what I've been told, the drier and expansion valve deal with the A/c component, not the heat. Can you clarify? Also, I can feel heat not only during acceleration, but when the car is moving in general.

[Buzzman]

I hope I don't come across as a jerk, but I've been reading through the thread, and still can't figure out how you guys got to a sunload sensor problem.
In the original post, you said the blower motor didn't work anymore after driving for a while.
After having seen this type of problem on here before, as well as experiencing this same type of problem first hand, I suspect it's nothing more than the amp. They are easy to replace, and cheap.
I'd go that route first. I'd try picking up a used amp from a wrecker if there is a junkyard near where you live.
As for the in cabin filter, I believe they were not standard issue on the Pathfinder.
(Mine did not have any. I had to do the cutout and install thing.)
When you take out the glove compartment to access the amp, you'll know right away if you have the filters or not.
Keep us posted.

[Towncivilian]

Not at all, any input is welcomed!

We're just trusting the auto HVAC diagnosis system with regard to the sunload sensor "problem". You're probably correct that the auto amp is on the fritz and replacement would be a wise idea.

My Pathfinder came with cabin air filters stock. Either way, it is an easy task to add them yourself.