I just purchased a car that had the 4th gen dash swap from a 99 T/A. The HVAC does not work properly. I only get air out of my defrost and if I need heat I have to go find the old 3rd gen cable and push or pull. Has anyone SUCCESSFULLY converted a 4th gen HVAC to work properly on a 3rd gen box??? Right now I can only control the fan with the 4th gen stuff.

Also one question I could not find any answer to.....how did the T/A's and GTA's with the digital dash control airflow?? I assume it had to be electric/vaccum controlled as opposed to the cables in other 3rd gen cars??? Is there anything that could be used to help on the 4th gen conversion???

 

Update....HVAC minus the AC is fully functional with all the 99 T/A dash and 4th gen wiring on the 3rd gen heater box. I just need to see why the previous owner had blocked off the left and right side vents on the dash.It turns out my selector was leaking air and would not operate any of the air diverters. A quick trip to the junk yard yielded the same controller from a 1999 Buick Century.

I used the hot/cold cable from a 4th gen 99 Camaro. It is very tight to the 3rd gen box. I am going to try out a 98-02 Firebird cable as I have heard they are longer by an inch. Not sure if is true, but I will post back once I have the cable. I simply shaped the lever on the bottom of the 3rd gen box to match the shape of the opening in the center of the 4th gen cable. I removed some material from the 3rd gen box and took a tip from d10pins and fabricated a bracket to mount to the existing bracket on the 3rd gen box. I can now control heat without fishing under my console for a cable.

On a sidenote I found out that fusor114 works very well on the A pillar conversion. I cut the 3rd and 4th gen pillars so they overlapped. I took a torch to roughly shape the plastic so the fit was better then plastic welded the seams. I followed a tip from shr00m and filled the open area with expandable foam. Then simply apply fusor114 and blend. It dries very quick as it is a two part application in a tube. It is a little runny, but okay to work with and it sands very good. I am not worried about a perfect finish as I have some material that is used on the door panels of newer Pontiac G6 cars. Its ebony and textured and will be a very close match to the dash.

 

some pics?

 

I will post up picks once I put my dash back together. What did you want, the a pillars or the cable????

Right now everything is ripped apart and like a fool I started something else on the car. I had a problem with my ls1 oilpan touching the stock k member on the passenger side. I have the old motor mounts off and am waiting for new poly mounts to be shipped up here to Canada. The car is up on stands right now and its not too fun to try to get in and out of the car when its up in the air. Mind you its not too fun underneath with the Hawks longtubes and the Drews crossmember either.....

 

curious to see how the pillars came out

 

No problem, I have the passenger side pillar ready to put material on, but the drivers side is still very raw so you can kinda see what I tried out.

I didn't install the dash, I am just the new owner thats finishing off small things. I noticed that how I cut the drivers side 4th gen pillar and the passenger side were SO different. The dash looks like it was more to one side than the other. Either way, a torch is a great friend for twekaing the plastic into shape.

I will post some pics tonite before I go any further on the drivers side. Whenever I get them covered I will post the "after" shots as well. The car is going into storage soon for the winter, so hopefully I finish covering them before that happens.

 

Hey post some pics of the cable and bracket as well, would ya? Going to be selling my car and need to finish up these same small things before I do.

 

Here are pics of the left side in a very raw form, but it gives you an idea of fitment.

 

Here are pics of the right side. I would have installed it tonite for the pics, but I coated it agian to fill in a couple of uneven spots. From here it will get a finishing sand and then be covered.

And Slep chaeck your PMs for pics......

 

It turns out that a cable from a 1994 Camaro is 27 7/8" from center to center. The cable from a 1999 Camaro that I was using was only 19" from center to center. The cables are the same, its just the 1994 is roughly 8 inches longer. It should be a good cable to use on the 3th gen HVAC swap just because of its overall length. If anyone else can document the year, make and length of their cable that they are using please post it here. It may help others trying to do the cable conversion.

 

bump any updates??
ill be working on the cable as well . form lt1 i believe
any pics how you adapted that cable?