MarkRak

Hi…New to this forum and need some help! My wife's 2004 Grand Cherokee recently started blowing very little air out of the vents, on both heat and AC, although the heat and AC temps seem fine. When I turn the fan control to high it sounds like the fan is on high, but there is very little air coming out of the vents. My mechanic (who I don't know if I trust anymore after 20 years!) told me that he checked it out and was positive that it was the blend doors….that they are plastic and typically will break at the hinge point. He also wanted between $1200-$1500 to remove the dash and repair it. I declined, went on YouTube and followed a video on how to access and repair the blend doors by removing the glove box, entering the plenum box and changing the doors out.

Needless to say I did this, but the blend doors were working fine so I didn't need to change or repair them. Now I don't know what the problem is.

Does anyone have an idea of what the real problem could be?

Thanks!

ThunderCougarFalconBird

I don't know if this applies or not to this model, but years ago, on an older car, the fan motor would run, but I was getting very little air. Turns out that the set-screw that held the squirrel cage fan onto the motor shaft stripped and the motor was spinning, but the fan wasn't.
Also, the intake for the fan motor is from your cowl just below the windshield. Make sure that nothing is blocking that. I had a friend who was afraid of getting water in there and so put a sheet of plastic over it...needless to say, no air made it into the cabin!

MarkRak

Thanks, I will check on this ASAP!

MarkRak

I checked to make sure there was no blockages under the cowl, but all seemed clear. I ran the Shop-Vac in there as far as I could and it didn't really seem that there was anything in there.... I was also able to reach down in and even feel the top of the blend doors, so a blockage is not the issue.

I'll have to research how to access the blower fan....does anyone know of a write-up? Thanks!

dave1123

On your WJ, the fan motor is mounted from the bottom with 3 phillips screws and comes out easily. You don't have to remove anything else, but you have to stand on your head to do it. LOL.

Check out wjjeeps.com for the info.

MarkRak

Thanks!....Do I have to evacuate the AC system, or can I just disconnect the battery and remove the blower?

MarkRak

Regarding the blower, some further research has found that it could also be the recirc door right above the blower. Is it as easy as dropping the blower and checking the door to see if it is broken, or do I have to do anything like evac the AC system before or after?

dave1123

You don't have to mess with the A/C unless you're going to pull out the whole heater unit and in order to do that, you have to pull the entire dash out as well. Once you get the blower out, you should be able to look up from the floor and see the recirc door. If you've left the battery connected, you can start the engine and observe the blend door as well as the recirc door. Just disconnect the blower motor and resistor first.

The reason they tell you to disconnect the battery is so you don't accidentally set off the airbag when you're working near it.

MarkRak

I dropped the blower as was suggested here. What was supposed to be 3 phillips screws turned out to 3 rusted torx screws. I could only remove 2 by locking their heads in small vise grips and turning them off. The 3rd was blocked by 2 thickly wrapped wire harnesses. Luckily I was able to sneak a screwdriver style torx up between the harnesses and remove the last screw, dropping the blower.


As soon as I put my hand up inside the housing box I could feel that the recirc door had dropped and was just laying on top of the fan…causing the blockage and lack of air going into the housing & coming out of the vents. Following some of the posts and research done here, I snaked 3 connected cable ties thru the recirc side of the housing (the side which is open like a “cage”) and around the loose recirc door. (this took about 5 tries because of limited space/vision to the area) I then pulled the cable ties tight, pulling the door tight up against the cage side, and cut off what I could of the excess cable ties. It is very tight in there, lucky my hands are somewhat small or I probably could not have done this.


I put the blower back in place using 3 new stainless steel screws, started the Cherokee up and had normal air flow back out of all the vents. The only downside is that this method eliminates the ability to use recirculated air, but it is certainly better than no air at all. Overall this took me about 1.5 hours.


Thank you to everyone who posted and helped out!

dave1123

Great! I'll have to remember that one.