Now that the seats and center console are out of the way it is time to start removing the metal brackets.There is a bracket that holds the wiring harness to the main frame. In order to get the wiring out of the way the connector body from the front harness needs to be removed from the bracket. There is a plastic clip that has to be released and then the connector body will slide up and off of the bracket. Remove the nut and bolt that hold the small bracket to the main metal frame. Then move the bracket with the rear harness still attached towards the rear of the vehicle. Also while in that area the two screws at the front of the main metal frame can be removed. Those two screws attach the bottom of the dash carrier unit to the center console bracket.
Now the two rear bolts can be removed and the bracket can be placed out of the way. The carpet can now be rolled towards the rear of the vehicle. You should notice that the carpet is not shown in the next few pictures. That is because I got ahead of myself in trying to take pictures for documentation. The vast majority of the pictures that I take are during re-assembly.
Here I am showing the black trim panel that attaches to the floor duct and covers the wiring harness and brackets. By the way the wiring harness should be under the carpet. As stated earlier I was doing a lot of inspection and testing during this repair so the position of the carpet and some of the parts are not always the same as one would see during disassembly.
The passenger side of the trim panel with the push pin retainer can be seen in the next two pictures. There are two push pin retainers on the driver’s side of the floor vent.
With the trim panel and the carpeting out of the way the last of the metal bracketry can be removed.
Now the under carpet rear floor duct can be removed. There are two push pin retainers that have to be pulled out. One on the passenger side and one on the driver’s side.
Now the main floor duct can be seen.
If you look carefully towards the right side of the floor duct, sandwiched between the HVAC case and the floor duct is the driver’s side temperature/blend door actuator.
The problem here is deciding how to proceed. I did a lot of research to find the best approach to removing the floor duct to gain access to the actuator. The “tricks” that I found were:
1. Use a pry bar to crush the floor duct down. Remove the far passenger side screw with a wrench. Follow that with using another pry bar to break off the remaining actuator mounting tab. Remove the actuator and re install it with only one mounting screw. Although the task would be done and the actuator would be replaced, I did not feel it was suitable for myself or my customer and he agreed.
2. Remove all three mounting screws that are accessible. Then pull on the floor duct to break the loop on the bolt hole so that the floor duct could be pulled out. I have done dash work extensively for the past 30+ years. I examined the material around the screw holes that were accessible and tugged around to get a feel if this option was viable and for me it was not. I strongly felt that the wrong plastic parts would break turning this job into a nightmare.
3. Loosen the dash assembly and the HVAC case so that one’s hands could fit in between the HVAC case and the firewall to reach the one hidden screw. I examined the fastener lengths and gauged the amount of room that might be gained and realized this would not work for my large hands and forearms.
4. Remove the dash, steering column and HVAC case according to the manufacturer’s instructions. The whole procedure is supposed to take about 7 hours. Five to six more from this point of disassembly. The refrigerant has to be recovered and the cooling system drained as well.
I have taken hundreds of dashes and HVAC cases out in my career and will likely take out many more. I understand the pitfalls that go along with doing it also. Most of the parts are made from plastic and they all become very brittle as they age. The heater and evaporator cores are made of soft metals that over time will harden and they too become brittle and subject to fracture. The circuit boards inside of all of the modules weaken. The wiring harnesses almost never lay back in the exact same places for a multitude of reasons.
All in all it can be quite a traumatic experience for all of the dash parts on any vehicle (new or old) to be removed and re-installed. All of this experience along with the anecdotal writings of others lead me to believe that if that floor duct could be removed and re-installed without removing the HVAC case and related parts the truck, my customer and myself would be much better off in the end. There were only two snags:
1. How to remove the floor duct without damaging anything?
2. What ill effects would come from leaving out the one screw that was hidden behind the floor duct? The one that was preventing the floor duct’s removal.
I contacted my customer and got his okay to test various theories. The first thing that I did was remove each of the three visible and accessible screws one at a time. Each time I removed and tested the effects of one screw being missing, I re-installed it and moved to the next screw on my list. There were no visible or audible side effects present with having any one screw missing. I repeated the tests with two screws and then three screws left out. Still no side effects. You can even see in the next picture with all screws still in place the floor duct actually rests on the floor board in some places. Also remember that there is another piece of duct work that goes over the foam gasket (Kind of reminds you of a sponge doesn’t it?) that is touching the floor.
I was looking at all of these components and thinking about why there were any screws at all holding the floor duct in place. A simple foam gasket and the assembled tolerances would be more than adequate to seal the seam between the main HVAC case and the floor duct and also prevent vibrations and noises. I have seen that same process used thousands of times while working on dashes for over 30 years.
Then it dawned on me. It was the assembly line process that dictated that the floor duct be attached to the main HVAC case. The case is not made on the main assembly line. It may not even be made in the same factory. This means that the completed assembly has to be packaged and transported to the main assembly line. It has to be unpackaged and attached to an assembly line arm. Then the whole thing has to be placed into the truck on the assembly line. A good bit of the time it will be suspended in the air with nothing under it for support. That means that the floor duct has to be attached to the main case. The manufacturer would not spend the extra time or money to install the case and then attach the floor duct to it, in the vehicle. Thank goodness they did not decide to attach it with glue. That would mean that the entire HVAC case assembly would likely have to be replaced if that actuator failed. Of course that would fit in fine with some who recommend replacing the whole assembly rather than fixing it anyways.
My conclusion was that although it may be less than perfect leaving that one screw out would have no ill effects on the vehicle or the customer. Keep in mind that I absolutely do not condone leaving screws out as a regular course of business but sometimes it just makes more sense. Especially when it has been thoroughly thought out and approved of by all parties concerned.
Okay now that I have addressed the concern of leaving the one screw out all I have to do is figure out how to remove the floor duct with that one screw still in place.