Damned Cold...

Alright Sherlock, riddle me this:

A dew days ago, when the temperature dipped into negative territory, I started my taco (2020 Sport AC MT) and while the engine ignition switch was in the start position, heard an awful sound (not an engine noise, but front end) as the engine turned over. The engine started as normal, albeit a bit sluggish in the cold, and I let it warm up for a 2-3 minutes while I filled my travel mug with coffee and donned my gloves to deice the windshield and scrape snow off the body. The cabin climate controls were on the def/footwell and somewhere in the middle of the fan range (they rarely move, my habit is to have the temps at HI and just use the fan to regulate interior temps). When I return to the vehicle I notice less than stellar performance of the defrosting. "Great, that awful sound was my blower motor stripping (probably plastic) gears, and now I'm going to have to pull apart the dash" I think to myself. I open the door and to my surprise the heat IS coming from the appropriate vents, but NOT at a the right velocity. "Weird, I can hear the fan blowing." I move the cabin fan speed control thru its range and indeed the fan speed audibly changes, but the resulting flow of air does NOT. It's barely there, almost like the speed is purely convective. I move the vent control thru its range and I can hear the baffle movement, and the resultant change of direction is evident at the appropriate vent, still in the same reduced convective velocity. Aside from checking the fuses in both panels, what else should I be looking for here? I've driven it once since, and checked what I thought were the appropriate fuses, but have not isolated the problem. I'm going to go through ALL the fuses, just to be thorough, but I fear that this is going to be a rabbit hole for someone like me who is technically unfamiliar with the 3rd gen guts. Is there an auxiliary fusebox somewhere else? Do the relays have an indicator if they have failed? I'd like to do this myself, and avoid the stealership. TIA

 

First check the cabin air filter behind the glove box.

 

Replaced at last oil change. I'll do it, couldn't hurt. I'd be surprised to find clues there...

EDIT: Well, color me embarrassed. That is dirtier than expected, although not enough to impede airflow. The squirrel cage visible underneath moves freely under finger input.

 

You might be right about the fan. If you’re hearing the fan speed change but not feeling any change in air flow, then either the fan blade isn’t turning as it should or something is blocking the air flow. ??

 

Mouse in the fan?

 

Or a cat...

 

Nothing IN the fan, just the cabin filter in front of it.

Apologies for doubting @RustyGreen, I started the truck and, absent that cabin filter, it seems to blow fine throughout the range.
It is 40° f here today so now I'm wondering what the hell that noise was? It's just some leaves and needles in the filter, hard to believe that ICE would have made its way to moving parts. The sound was like interference of stationary vs moving parts. I don't know whether to be relieved or anxious...

 

Might try and check the vents in back of cab, and under hood at cowl. Also, if you can see the squirrel cage, maybe put a mark on it with bright paint pen, then cycle through fan speed and see what it's doing. Hope you can get it figured out, being cold stinks! Edited, I see you checked fan!

 

No but the closer I look, the more I think mice might be setting up shop...

 

Makes sense; the cab's gotta breathe. I'd checked those vents at the back of the cab before in my quest to isolate road noise. They are pretty...not airtight.
I'll definitely put hands on the cowl today, if that much stuff is getting to the cabin air filter then maybe I have an issue up there.

 

Ugh! There has to be something that is available to spray on wires that would make then unpalatable to rodents. Seems a lot of fellows have this happening to them.

 

Could be. My truck sits out year round, and in the fall I get a lot of leaves and those whirly maple seeds packed in my cowl vents. I always have to clean them out every so often.

 

Yeah, there are more than a few threads here about home remedies and suggestions about adopting predators to fix this. Seems like a design problem though, not much you can do against mother nature. WHY do they taste SO GOOD!

 

"Ugh! There has to be something that is available to spray on wires that would make then unpalatable to rodents. Seems a lot of fellows have this happening to them."


I have a friend that recently experienced some RV wiring damage due to mice. It was recommended he use this:

https://nhoilundercoating.com/product/mouse-out-2-cans/

I'm still waiting to hear back from him on the results.

 

Fluid Film, Wool Wax, or Surface Shield. Lanolin based corrosion protector. Smells terrible, rodents hate getting it on their feet, tongues. Bonus, it helps prevent rust and aluminum oxidation. Ski

 

Yeah, I'm betting your cabin air intake is full of leaves (or possibly the mouse nest).

 

Not a bad idea to bang on your hood during the cold months to scare off any cats or rodents that were trying to stay warm and dry. Rodents can cause a ridiculous amount of damage and a huge headache to boot.

 

If the engine running frequently doesn't deter them then occasional banging on the hood won't either.

 

Maybe try playing some Sarah McLachlan at them to scare them away.

 

Nice! I spray down the underside of my truck annually with woolwax, and spray areas under the hood with fluid film. Hopefully I can stay rust and rodent free!