[Solved] HVAC tick

Whenever I have the fan set to “HI” there is a constant ticking noise coming from under/behind the glove box. If you switch the fan to any other setting it’s silent. Doesn't matter if the A/C is on or not. I haven’t stuck my head under there and looked at it yet; but is there a common part that goes bad or a specific thing(s) I should check?

 

Pull fan, check for debris.

 

This is the one thing that kind of sucks about or trucks not having cabin air filters. After you pull the fan (1 harness and 3 10mm screws) might as well clean all of the inside as far in as you can reach just for good measure.

 

I mean, I'd go so far as to drop the blower motor and carefully pull the blow motor resistor, and flush out everything.

@Zach_795, @GXPaycheck is probably right. It could be a number of things causing the issue because it's literally a wide-open hole above the blower, straight into the cowl. We have no cabin filter (unless you have a Sequoia, then maybe?). Chances are if you park under a pine tree, there's a pine needle or two stuck in there, slapping into the fan blade at every rotation. The fan could be on its spindle off-center. Bearing could be worn out. There could also be debris farther up the line from the fan, at the evap coil, and it's slapping against the evap coil.

Best 1st step is to pull the fan like @The Black Mamba said, but while you're in there, be aware you can (and should probably) attack this cleanout from multiple angles if you really want to deep clean. Specifically, the red box here is your blower motor resistor - remove it carefully, two bolts holding it in. You can see the evaporator coil back in there, which is where your AC system pushes coolant through inside the ducts so you get cold air when AC is on. Then the blower motor in blue under the glove box. PHM posted a great set of pics showing his cleanout, but I can't seem to find them. I posted this, which shows what happens if you're not carefully about removing the resistor, and also shows the debris I had in mine (also pine needles) and how to refresh your HVAC system: https://www.tundras.com/posts/3126837/

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Pull the fan and check for trash. It may be the motors brushes causing the notice also

 

Just got finished taking the fan out. There was a pretty stout helicopter type leaf stuck in the blades. Pulled that out then blew all the dust off the fan with a compressor. Then I took a wet rag and wiped down everything up in the vent hole as far as I could reach. Good as new.

 

Love an easy fix!

 

I have had this issue fo the last two years. I just turn up the radio.

 

BINGO ^^^. I like to suggest Led Zeppelin's: How The West Was Won live album.

 

Zeppelin 2 or physical graffiti never misses