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Dash and HVAC Box

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Ok everyone I have the parts coming in Today and Tomorrow to replace my Heater Core.  I am also going to swap out my Evap and Blower motor while I have the HVAC Box out.  To top it all off I have needed to replace my Dash for awhile now so one is on the way from LMC Truck and that will be going in as well.  Mike I have seen your video on You Tube and it breaks things down pretty well for the HVAC Box.  If there are any little tid bits or pieces of advice anyone has please share them with me.  I will write up a synopsis of how the job went when I am finished.  Thanks


Probably should have put this in 2nd Gen Non Powertrain Related if someone can move this that would be great. 

Edited by deehammer
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I used this for the most doing the same job you are about to tackle.

While it can be a bit of pain it is not that difficult just time consuming. It will help to have an extra pair of hands to get the screws in the dash on the driver side. The HVAC box has mounting screws that run vertical and horizontal so be careful pulling it out. I ended up breaking a couple of them. I posted up my experience with it several years ago with pictures but do not know how to find it anymore. I think i spent 2 and half days doing it all but definitely took my time. This included one trip to the parts house and 3 to the beer store.

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While the evaporator is disconnected from he system block off the A/C lines to reduce moisture infiltration.  Replace the expansion valve and accumulator with that evaporator,  add a few ounces of PAG oil then evacuate and recharge the system.  I know more stuff to get and do but the A/C system will love you for it.      

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So I got the job done.  Really not horrible just time consuming.  There is one issue though....I cannot get any heat.  All vacum lines seem to work (changes from floor to dash to normal) fan speed works fine just no Heat.  The new Heater Core gets hot like it should no problem.  I am thinking it is probably something I did but am stuck in that "everything went just fine" haze right now. I do not have the A/C system recharged at this point but that should not cause an issue.  I am guessing the selector switch from Heat to Cold is not functioning properly and even though I had the HVAC Box out today I do not know exactly how it works.  Help me out here guys in need some advice.  Would really like not to pull the HVAC Box again but I will do what I have to....Thanks


Further investigation on Mikes article section revealed a quick video about the Blend door. The motor "operates" when moved from hot to cold and then visa versa. I can hear the motor run for 5 seconds or so after switching back and forth.  Arrrggghhhh I am thinking I need to pull the HVAC Box again.  Maybe I did not put something together correctly after I had the box split this morning.  I remember everything lined up correctly but maybe there was something that I missed like the darned blend door shaft being aligned which I can no longer see thanks to the the new Dash isntalled :thumb1:.  Thanks again for any advice. 

Edited by deehammer
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The shaft for the Blender door was not aligned correctly.  Had to pull the entire HVAC Box again.  I feel like I am an expert at it now took me about 90 minutes.  Mike mentions it on his video but you have to make sure that the Blender door shaft is aligned to the other side of the box.  Before installing everything I hooked up the power and tested it out to ensure the shaft moved back and forth.  You can see the movement from the top of the HVAC Box by looking at the pin.  

@dripley yeah I checked the coupler as well while I had it taken apart it looked good.  

Thanks to all for the advice on this project.  Took a total of about 12 hours (without my rework) which included the following being replaced:

New Dash From LMC Truck...seriously I could not imagine a part fitting better this dash looks, feels and fits great.  The screws from the backside were the hardest part of everything I did.

Heater Core  I have pictures of my old one that I will post dang that thing was not in good shape.  Also put on new heater hoses the old ones were not worth saving as they were stuck on so bad I just cut them off.

AC Evap at least 30% was gummed up with dirt and crud.

Blower Motor and Resistor because I felt like it.


Overall it was not a terrible job.  I got to know my truck a little better and it looks and functions so much better!!!  Below are some pics not really in any order but I thought some might like to see.  If anyone has anything specific they would like to see let me know I have quite a few pics.  Also if anyone is in need of advice I am pretty darned schooled on how to do this job now!!!  














Edited by deehammer
Adding pics
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