Air Conditioning / Fan Help

First post here. I inherited my dads 2000 Tundra (4.7l) after he passed away last year. I actually used to drive the truck in high school (Im 35 now) and with only 142k on the odometer and no mechanical issues I'd like to keep this thing going.

Ever since I acquired it, the AC would blow 'cool' not cold air with hardly any change in force even when when on number 4. The blower motor sounds like its spinning faster but you can hardly notice a difference. Additionally no matter where I choose to have the air blow out, it doesnt change, just blows out the dash vents.

I schedule a service appt with a reputable shop in my area of Maryland, but was hoping to see if anyone has had this issue before and if there was anything I could do myself to inspect/fix this issue prior to taking it to the shop.

Thanks.

 

Welcome to the forum. Sorry for your loss. Tons of helpful folks around here.

 

Everything you need to know about that Tundra: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

Given you're in the rust belt, before you dump money into it, double-check the frame as you'll see ample warning about in that thread.

It sounds like the HVAC controls are bound and/or skipped teeth and/or something is bound. Check out @BubbaW's comment in this thread: https://www.tundras.com/threads/climate-control-knob.126117/#post-3222836

Specifically, see the diagram he shows. Then watch the video starting at at 5m30s mark and verify that's not your problem, that the cable didn't slip. That's probably one of the more common causes. But the video covers all of it.

Some guy just recently posted on here that his cable in that kick panel next to the gas pedal jumped off recently, I think he had similar symptoms. I dunno if a shop will be able to help with this, but you may be able to fix w/that video.

 

@shifty` thanks for the tips! i’ll take a look at this tomorrow. Dad had the frame replaced as part of the recall, i crawled underneath of their recently and frame still looks great. there is some rust on the bed above the rear passenger wheel well but i’m not concerned about that for now

 

I had a similar issue when I got my truck, this may or may not apply to you.

I found out that a little plastic piece behind the temp control knob had broken off.

This part controls the hot water (coolant) valve under the hood, on the firewall, that controls the flow of hot coolant to the heater core.

Without this working, your heater is stuck always ON hot, even with the AC running, which severely cuts down on how well the AC works.

You can check this easily, by trying to move the valve by hand, from the firewall side. If its connected, you won't really be able to move it, if its broken like mine, it will move easily.

As the part is $150 to fix it, for a stupid plastic gear, I just flip mine manually between heat and cool in spring and fall.

 

@Aerindel do you have a photo of this plastic piece I should be looking for?

 

I don't....its in the black plastic gear assembly behind the temp control knob, its just a little arm on a gear that slides a wire in and out of the firewall. If you pull the climate control console out, which is easy to do, it's really obvious, but hard to describe.


The valve itself is under the hood, near the middle of the firewall, above the engine. Its easy to find because there isn't anything else that is on a coolant hose in the area.

 

@Aerindel ok thanks, i’ll take a look under the hood tomorrow and post a pic here to make sure i found the right thing

 

From inside the engine bay, I think this is the module being talked about. It's also a trap point when refilling coolant, and part of the reason you need the heat on full blast when flushing/adding coolant, so air and fluid can circulate through. Over to the left of it where the hoses connect into the firewall should be the entry/exit to the heater core IIRC. Anyway, you may be able to test the functionality by simply turning the air on full blast, AC off, and knob set to coolest in the early morning when temps are cooler. Is there any heat? If not, then spin the temp knob to full heat - does it get hot? If you spin it back to full cool does it get cool again? If so, knob may be working.

Tell us a little more about the fan speed thing you mentioned earlier. Normally if the fan resistor is going out, at least in my '06, only the highest setting works. It's either on-full-blast or off.

 

PS - blower motor resistor location is here, and it's what controls your fan speeds. If malfunctioning, you may lose speed stepping for your air. But note that there *ARE* doors inside the vents that, if the controls are binding up or not working correctly, can stop airflow coming thru the vents, so if you're not missing the lower fan speeds, I doubt the resistor is the issue.

https://www.tundras.com/threads/wha...-gen-tundra-today.2558/page-1571#post-3126873

 

@shifty` Thanks, I found a second video from the person you linked that showed where that cable is and where it leads to in the firewall, but thanks for confirming the location.

The fan speed....so i can freely move between 1-4 as it normally should and i can hear the fan blow air with more intensity as i move up 1-4, but the increase in air coming out of the vents is marginal....there is an increase, but not much. should I drop the blower motor and check for any debris?

 

You could, but more than anything, it sounds like you have some controls binding and you need to get in, review the cables as mentioned in the other thread. Either one of the blend doors isn't opening because it's broken or unhooked, or one of the knobs isn't functioning properly. There's one other post I'd direct you to, but I need to find it. I don't have a good mental image of all the doors in the system. I know @BubbaW has posted good content in the past on this and I usually end up finding his replies helping others on here when I'm digging back thru info.

There's one other person who also found something on the passenger's side of the center dash last year IIRC. Let me see if I can track it down.

 

@shifty` Awesome, i really appreciate all the help so far. I plan on digging into this over the weekend.

 

I sure as hell can't find it but I'm 100% positive someone on here found an issue in some duct control between the ECU and center dash on passenger side. They had to rig up a temporary solution of some sort. I even asked them to take extra pics and post them, and they did. Sad I can remember it but can't fathom the keywords needed to pull up the post in this subforum.

I did find this thread, it covers some of the stuff with controls with more videos, including fixing the controls on the driver's side next to gas pedal - this guy found his problem was the flap @Aerindel mentioned causing his air temp problems:
https://www.tundras.com/threads/no-a-c-or-heat.109191/

I'd be curious to check for rodents also while you're in there. And carefully remove the resistor (since the ceramic can crack) and use a vacuum to suck out all the debris often find inside the evap coil housing ... no cabin filter for us!

EDIT: Nevermind, this was the issue I was thinking about: https://www.tundras.com/threads/cold-air-behind-glove-box-solved.123112/

Basically the air recirc door was busted. Check that thread also, maybe that's your issue.

 

Since you’ve got a replacement frame, I’d consider doing something to preserve it like woolwax or the new PBlaster stuff you spray on.

 

@JasonC. will do.

 

Speaking of….

 

Well to update everyone who helped me on this thread.....I checked all the cables for air direction control and the temperature...everything worked as it should. I even took the truck in to a local shop and had them purge the refrigerant, check for leaks, and fill it back up. no issues and i could tell the AC was running cooler but still was not blowing a lot of air. At this point I was convinced that i had an airflow obstruction. Today, while enjoying the break from the oppresive MD heat I dropped the Denso fan motor and looked straight up (after doing some serious stretching). Apparent above the fan motor there is two foam pads in the duct work that should be attached to the walls of the duct.....well one had unsecured itself and blocked 2/3 of the hole above the fan motor. I moved it back against the wall of the duct (this will likely fall back down) resecured the fan motor and gave it a test.....BOOM we got it fixed!

thanks to everyone for the tips along the way....I think the next project for this truck is to secure a set of the alloy wheels that came with the first gen....the steel wheels on dads truck have seen better days.

 

Was it this problem, I linked 3 replies up? https://www.tundras.com/threads/cold-air-behind-glove-box-solved.123112/

Just curious if we can add you as a 4th person affected by this issue.

 

@shifty` sure as hell is, guess i never clicked that thread. add me as the 4th person effected by that. would love to get it fixed properly as i plan on keeping the truck. but as long as i know the problem if it happens again i’ll be able to fix it in 10 minutes