I'd like to say Thank You, Thank You, Thank You, Thank You, Thank You, Thank You, Thank You, Thank You, Thank You, Thank You, Thank You, Thank You to TheJuicer, GnPower, Dokkenette, Dimeblazer, Kennycraze and the others that posted solutions, tips, advice and photos on this Floor Heat topic.


I was trying to work up enough courage to take the dash out to replace the defrost door on a 2004 Blazer, but once I stumbled across this forum and learned about the idea that replacement could be accomplished in a much easier way, I was saved.


After reading your posts and seeing various photos, I couldn't wait to get at it. You guys gave me a complete understanding of what needed to be done and how to do it. As a result, the job went smoothly and I was hoot'en and holler'en when I got the end of that door to pop into place. Man, that was an awesome moment. I tried the "hanger trick" first to diagnose that the door was in-fact broken before proceeding with the work. So, even that was a helpful bit of advice. I used some masking tape to outline the size and shape of the hole to cut. So, it was a visual guide to make a nice neat cut with a Dremel tool, which was like cutting butter. I did get confused with how to put the spring back on the lever that connects to the actuator, but I just went to the computer to see a photo and was good to go.


Again Thank You, Thank You, Thank You, a thousand thank you's. I truly appreciate your willingness to offer your experience. You saved me a huge amount of time, aggravation and likely cut-up hands. But more importantly, you've probably saved other people $600.00 + who would've opted to pay to have the dash taken out to fix the problem. This solution you've offered is a really big deal.

 

Welcome to the forum and thank you! Thats what its all about, helping out the next guy and keeping money out of the shop owners pockets.

I have another blazer that im going to have to do this to before winter rolls back in, i think i'm going to make a video when i do it and put it on youtube, i'll post a link here when the time rolls around.

 

I know this thread is old, but I just ran into this problem on my 2000 Jimmy with 250k miles on it, and this seems to be the best information I've found so far. I got the bottom panel off and watched the actuator while switching modes, and it does move. There is minimal movement when switching from floor to floor/defrost mix, but obvious movement when going to full defrost. Same in reverse, minimal movement going to floor/defrost, full movement going to full floor. But I never get heat out of the floor unless I use the coat hanger trick to push the door open. I tried wiggling the white gear/rod at the top and I can't get any movement there, but not sure if that only happens once the actuator is unhooked. Anyway, it feels solid with the actuator attached. I'm assuming the door is broken inside since I never get floor heat unless I use the coat hanger. I am just trying to be sure before I order the part, and before cutting into anything. Also wondering what the actual measurements of the door/flap are? In the pictures posted, it looked like a pretty large opening that people cut, but looking at my own vehicle, there doesn't seem to be that much room to cut a hole where you can get your whole hand up in there (I am a woman and do have small hands so that's a bonus). So how big is the door/flap and how big is the hole you all cut? Guess I'm just looking for more guidance before attacking this any further. I would use the coat hanger trick and forget about it, but that blocks off my defroster completely until I drive around awhile and the door falls back shut. Definitely need defroster sometimes!

P.S. I have a floor shifter so removing the center console was not so straight forward. I also thought if I took the ashtray module out it would give me more clearance, but after removing the 2 obvious screws, I couldn't see any other screws, so I guess I have to take the instrument panel bezel off to get to those. I tried removing the ashtray as someone suggested, but ended up breaking one of the retaining clips, so now I've got to order a whole ashtray/frame assembly....least that's all I've broken so far.

 

After removing the console tray( mine are all autos) I cut a 2" tall by 6" long opening and was able to get my hand in to remove the blend door.

I got impatient waiting 4 days for the new one to come so I drilled the the stub end of the broken one where the actuator arm connects( they break just inside duct) to down the center with a 3/16" drill and the door itself 1/8" and gooped the joint up with JB WELD and ran a number 8 x 1-1/2" sheetrock screw in it and has been working fine for over 2 years now.

If my repair fails at least I have a new one to install and I will take longer to pull the console as the access hole is already there. ( hole is covered with the piece I cut out + duct tape) and the console covers everything nicely.

BTW this repair only took me about 2 hours to do thanks to the info I read on this forum.

 

So in your opinion, should I go ahead and order the door before cutting into the duct? I mean, the actuator is moving, even though it seems a little sluggish at times, but it does go full defrost and full heat. Can I assume the door is broke inside, even if I can't wiggle the white gear/rod outside of the box?

 

And do I have to pull the actuator to get this job done? I've read it just has to be yanked out of there, no screws or anything. Any guidance is appreciated.

 

- they clip onto the bracket so just carefully pull it loose, then unhook them from the gray plastic piece that is actually going into the HVAC box.

just want to mention I read through a lot of this thread if you aren't sure what the issue is this thread really kind of points you towards a really difficult job when their may be a much easy solution to test first. i went to harbor freight and bought a hand operated vacuum tester/brake bleeder. then o'reilly and got a misc vacuum line connector kit (t's, y's, etc) and vacuum line in the two sizes these trucks use. If you have a 4x4 these are must have tools. anyway..... take down the hush panels under the dash pull the 2 actuators on the driver side and the one behind the glove box. be delicate and wiggle them loose and unhook them. this can be done fairly easily on 98+ vehicles. then test them with the vacuum tester they should all move straight in and out when you put vacuum to the right spots if they don't move, tilt, or loose vacuum they are bad do yourself a favor and replace all 3 even if only one is bad if you haven't had any changed yet. the other easy way to tell if it's a vacuum issue vs broken blend door is under prolonged heavier acceleration the vents go to windshield defrost or you just hear the air changing direction in any way. Also if you hear a hiss at the HVAC controller this is a sign that there is potentially a vacuum leak at one of the actuators (or the controller has failed) that's pretty much the easiest way to know it's vacuum loss and you need to find the leak. either the fender/hood canister isn't connected, the vacuum lines are rotted, the t-case switch has failed and is pulling gear oil through your whole HVAC system, the HVAC controller has failed, the vacuum check valve near the brake booster has failed. really are tons of easy places to look before you go ripping the whole dash out or cutting holes into the HVAC system

I know its' probably all been covered in this thread and this may or may not help anyone but i figured i would drop the things i learned in the last couple months into this thread it may save someone a lot of time, money, or both. in my case the t-case switch was bad, gear oil through the whole HVAC system, 2 out of 3 actuators had failed, vacuum canister was disconnected, lines were all rotted and air was leaking. i had so many issues i thought i would never fix it but now it works perfect.

 

Thanks. So again, can I assume that the door is broken, since the actuator is moving, but no heat to floor unless I push the wire up in there to open the door? I need to order the parts before I cut into the box.

 

If you don't see the actuator move 2 or 3 inches then it's not running a full run. Pull it down and try it then and see if it moves the full run. If it does move the door by hand and see if it is stuck

 

I'll try taking the actuator loose and see if I can get any wiggle out of the door stub before ordering the new door. I think I'll buy a new actuator too anyway, while I have it torn apart. Now am still trying to figure out how to get that darn ashtray module out that I broke....