2002 Ford Ranger Edge 3.0L

When the HVAC dial is on max heat (all the way in the red/to the right) everything is fine, nice quiet and clean. But when I start tu turn the dial to the left (towards the blue), after about 1/4 turn, I start t get the crunch and rustle of leaves, twigs, and other various detritus in the blower, and the awful odor of shredded dried crap coming out of the vents.

So I'd like to find the air pathway the "Cold" selector opens up so I can get to it and clean it out with my wet dry vac. Can anyone point me in the right direction? Thanks

 

Fresh air vent is under the welded in cowl between hood and windshield, on passenger side, so no access

But you can remove the blower motor in engine bay and vacuum in there and reach in and up into the cowl area to pull out any debris

The TEMP control **** in 1995 and up Rangers operates an electric motor that controls the Blend Door, which is inside the cab
The Blend door directs air from the blower, either thru the Heater Core(HOT) or around the heater core(COLD) or anywhere in between
So nothing to do with fresh air vent

Fresh air vent is always open EXCEPT when you turn system OFF or set it to MAX AC, this closes Fresh air vent, and blower would then pull air in from inside the cab, under glove box area

 

Well I just took my blower motor out and cleaned everything in there. I cleaned and vacuumed around the heater core too. But I didn't see any place the air would flow other than the heater core. Where is that airflow going through? I just need to know where to stick the vac to get the debris out. If it is downstream from the blower motor, then there has to be an opening somewhere

 

There isn't

And you can't get to heater core from blower housing, heater core is inside the cab, you were vacuuming the Evaporator fins, part of AC system

Fresh air vent-------Blower motor----Evaporator(AC)-----FIREWALL----blend door/heater core------------cab vents

Under the glove box there is a white vacuum hose connected to the Fresh air/Cab air valve, this valve is activated in MAX AC setting, so blower then pulls already cooled air from inside the cab to re-cool it vs pulling in hotter outside air(summer time)

Just FYI
AC only has on or off, there is no high or low, or temp control, MAX AC just means re-cooling already cooled air from inside the cab
Temp control is via heater core air flow only, i.e. Blend Door
Heater core at 180degF can easily over power AC at 40degF

 

What Ron describes above appears to be the same design as my 1996 B3000/Ranger. You might want to look at this post where I drew some arrows on the microfiche exploded drawings:
clean out climate heater box?

 

That doesn't make much sense. Let me make some drawings



When dial is set all the way to hot


When dial is set to cold

 

Do you have a ist of what the numbered parts are? Because as it is it doesn't make sense, it looks like #4 is the heater core, and #5 is the blend door, which means the air is always heated even in AC mode? Or if #4 is the AC fins, then the blend door must have a path to send that cooled air to the cab without going over the heater core so it doesn't get heated up again, where is that path?

 

All air from blower goes thru the Evaporator which is in the Engine Bay "box", assuming you have AC
Air then goes into the cab, thru the firewall

Blend Door then directs that air thru the heater core(HOT on temp ****), or around the heater core(COLD on temp ****)
If Temp **** is in the middle then 1/2 the air goes thru heater core(heated), other 1/2 goes around it(not heated)

In COLD all air goes around heater core, no air goes thru it

Diagram here: https://www.explorerforum.com/forums...-3-jpg.318034/

11 and 6 are in the engine bay "box"
5 is in the cab, Blend door
If you draw a line after 6, thats the Firewall
In COLD setting blend door covers heater core so no air goes thru it
In HOT blend door opens and ALL air goes thru heater core

 

That's a cleaner system drawing than me using the microfiche. The only thing I'll add to Ron's post above is that No. 16 in the diagram is a "heater water diverter valve" that cuts off water flow through the heater core. I haven't verified this on my truck, but think I saw such a vacuum-operated valve under the hood of my 1996.

The bottom line is that (as RonD wrote), if there's crap in the system, it's probably on the intake side of the AC evaporator, so clean by taking out the blower fan, get a compressed air nozzle, and blow that stuff out.

 

OK, so going off that diagram, this is where the debris must be. How do I get to that spot/where is that in the truck?

 

I doubt it, only way debris could get in there is if its a "mouse house", have you had a mouse problem?

Air comes in thru 8 or 10
Then Air Flows out from 11 thru 6 and into the cab, then passed 5 and out to the vents, 3, 4, 19 and 21

But if you want access to the blend door area watch the video



HEADS UP
On the left in video is the VACUUM Connector for vent control, those are vacuum hoses not wires
At the top is the Blend door actuator electric motor, those are wires, that is the part that breaks and no TEMP Control when that happens
If you do cut the hole then DO NOT force the Blend door open or closed, you will break it, turn key on and use the TEMP **** to open and close the blend door

 

I bought the truck used so it may have had a mouse issue in the past. I saw that video, and I'm not going to take a dremel and do anything destructive like that. Silly that they wouldn't pout an actual removable door somewhere to allow access to the blend door area.

At this point my plan is to turn the temp selector all the way to cold (to close the blend door), pop off the radio bezel to unrestrict airflow out of the top vents, pop out the blower motor again, and get my leaf blower and blast air into the blower motor area and try and blow out anything in there out the vent area and into the cab and then vacuum it up. Without any way to non destructively get to the area to clean it I can't think of any other way to do it

 

Slugger, if you look at the (very good!) diagram you posted above, the cowl inlet (8) and cabin inlet (10) both flow into the fan (11). You can get to either of those when you remove the blower fan, and you can get to the cabin inlet but pulling down the glove box. If plant trash comes into either of those inlets and makes it through the blower fan, it hits the AC evap coil (6) which has passages too fine to let much trash through. Said another way, any trash should get trapped between the evaporator (6) and the blower (11), and you can get there by removing the blower motor.

Of course, you might have gotten a mouse nest entering through the outlet vents 3, 4, 19, or 21. Now, if you did have debris in the location you show by the flapper door, it would probably be blown out after a bit just by flipping over to AC and turning the blower to high. Do you get any nuts or crap coming out your outlet vents?

I also blew compressed air up through my floor and dash vents and got zip coming out. The only thing I still might try is to use my shop vac as a blower and blow through those vents (less pressure, but way more airflow than the compressor).

I totally sympathize with you on this. It kind of reeked in my truck and, like you, I was thinking about taking a Dremel tool to the cabin airbox. But it's a lot better since cleaning out the debris in between (6) and (11), foaming the evaporator (6) with coil cleaner (get the stuff with the tube made for cars, not the spray stuff from Home Depot like I did!), and spraying a full can of Lysol through the system using the cowl vent and cabin vent and using setting for both heat and AC. Still waiting for the Lysol smell to go away for final judgement. LOL

 

LOL, I guess that works, and you could inspect/clean/blow-out the system from there. But if it's just the heater door, replace the actuator.

 

When the temp selector is full on heat, there is no issue. That means the issue must be downstream from the blend door. Which means it can't be AC Evap coil.

With no way to get to the blend door, I'll just have to use air to blow out what I can and hope it clears up

 

Ok, makes sense. Kind of what you wrote in your original post - and it does sound like maybe a mouse got up in there.

But did you already clean out the inlet and fan box? You might as well start there. After that, the only thing left to do would be to cut to a flap in the box like the video RonD posted, I really don't think you'll hurt anything doing that and if it solves your problem. A little Gorilla tape would close it up satisfactorily.

Good luck!

 

Yes I had the blower motor out (I took it out and cleaner it all out) and I cleaned out the blower motor housing, wped it clean, and used a shop vac and compressed air as much as I could to clean it out. BUT I did that with the temp selector all the way on Hot, so I missed the area behind the door when it is on Cold. I'll be moving the temp selector over and basically repeating that cleaning, I may no yank the blower motor again I may just put the blower on max with the radio bezel removed and see if that is strong enough to blow out the gunk. With the AC evap coil in the way, I don't know if I can get much more air pressure into that area than what the blower motor can generate itself.

 

Engine running
Center Bezel off, i.e. open panel vents in the center
Select PANEL on the vent selector, the 2 or one center panel vent would be closest to blend door
Blower motor on HIGH
Move temp **** from cold to hot a few times while vacuuming or blowing into center vents

 

I'm hoping that does it. I can try and pop the blower motor out and get a leaf blower aimed in there, but with that AC evap in the way I'm not sure how much airflow will get through. I'm going to get my camera scope and look down there as well (from the vent side). If there is anything stuck in there, maybe I can disturb it enough for the blower to get it out.

 

Watch out.....................it may look back, lol

 

I'm waiting on this one, slugger (the endoscopic camera). Drove old truck to GF's last night. Cold, heat on high. The Lysol smell is completely gone, replaced again by the foul smell of whatever got me working to clean the HVAC system in the first place. Crap, I still smell it this morning.

Some other ideas.
1) I tried to open the AC evaporator case weeks ago, but couldn't get it to come apart, and didn't want to damage the AC components.
2) Also tried to pull the entire air handler box off the engine bay firewall, but either the AC lines are too stiff to let me move the whole assembly back or there's one more nut attaching it to the firewall. (I only found 3 studs, maybe there's a 4th one?)

Last night I bought two cans of the proper coil cleaner ( ), but will probably shove a tube connected to my shop vac up the floor vents to see if I can dislodge a nest or whatever. Good lord this thing reeks.

Please post up when you inspect with the camera!

 

Follow-up on last post...

a) Bought an endoscopic camera for $30, but was unable to find any mouse nest. My guess is that I couldn't get the camera to feed up through the vents in the right direction.
b) I'm thinking of just drilling two holes, one in the main heat/cold flapper area under the glove box (see video posted by RonD in post #11) and the other one being in the evaporator case in the engine bay, but on the other side of the coil that you can't access from the blower side. Then I can feed in the endoscope to the parts I can't reach from the vents.
c) I found out there are 4 studs holding the air-handler box to the firewall (item 2 in my preceding post #27). Three of these are located in the engine bay, 1 above the blower motor, 2 on the top right side of the evaporator case, and 3 at the bottom of the evaporator case on the right side. No. 4 is located inside the cabin below the glove box, This is probably less than 30 minutes work, and if I can just pull that airbox and evaporator case back from the firewall, I can see into the upper areas I (and sluggerbaloney) want to inspect, and probably clean out anything in there without needing to cut flaps or drill holes.

Removal of the air handler box (with evap core) is shown in the video below, and stud inside the cabin is shown at minute 21. I'm hoping I can just pull the box back a couple inches from the firewall so I can sneak the camera in there and clean out any nests found.

Replacing leaking Evaporator core from a 1998 FORD Explorer," target="_blank">Replacing leaking Evaporator core from a 1998 FORD Explorer,

 

The smell you have is likely due to buildup on the evap core. This smell will NEVER go away until it is cleaned off, completely.
It's essentially 20+ year old dirt and dust that has gotten wet, then dried, then wet again, over and over. Think of a basement with moisture problems.

Buy a can of KOOL-IT and spray the core/HVAC system down with it. You can do this through the drain (suggested on the can) or through the blower motor opening, with the motor removed, of course.

Like mentioned, there are only two ways that debris can get beyond the AC evap core. Either someone dropped something into your vents, or an animal made a home in there.
The EVAP core is basically a wall that all air has to pass by to get inside the cabin.

 

I'm curious if this ever got resolved by the OP.

FWIW, I bought and endoscopic camera and did not find any nests coming up from the floor vents, the dash vents, or the defroster vents. I ran a 24" long skinny dryer lint brush through all vents and did not free up anything other than dust.

I cleaned the AC coil using Kool-It Evaporator Core Cleaner - liquid came out dark black and smelly. Now the evap core is clean as a whistle.

Per my post (#22 above) you can pull the entire air box in back from the firewall by removing the 3 nuts holding it inside the engine bay (2 on top, 1 on lower right) plus the 4th nut from inside the cabin. The air box will pull back from the firewall about 1" without removing anything else (e.g., leave blower motor, hoses, etc. in place and pull it back as one unit), This is enough to sneak in an endoscope camera in.

The pic below shows the engine-side airbox pulled back from the firewall. You can insert the endoscope and see the AC evap core or insert into the cabin airbox. With the engine running, you can move the flapper number 5 using the dashboard AC controls and expose one side of the heater core (clean in my case).

The engine side airbox (parts 6 thru 11) is completely clean (blower fan removed to clean out debris on one side of the AC evap core) and the Kool-It cleaner to clean the evap core (inspected with endoscope).

Looking in from the firewall is also clean in the region above the heater core (between parts 5 and 17).

I haven't found anything coming in from the floor vent 19 or any of the other vents.

Still have the foul smell and doesn't matter if the system is on AC (flapper valve 5 in the down position covering the heater core) or in the heat setting (flapper valve 5 up diverting the air through the heater core). Smell is worse when the air is heated, but still smells in any combo of AC/heat settings.

At this point, am thinking of just cutting a hole into the lower part of the cabin-side air box (what would about where the number 18 is below).

Not sure if the smell is from a nest, a dead critter, or just dried mouse pee.

 

I have not tried it yet, because it is winter so I have the heat on full blast anyway. This will be a spring/summer project.

I'm just going to insert my endoscope in through the vent and then snake it through that way. For your situaitonl if it is somehting dried on the inside of the vent, try spraying some mold armor in there. That kills and cleans anything.