I noticed a mice problem with a Vette I bought so I pulled out all the interior seats, carpet, jute, etc. I removed the dash pad and noticed some mouse fluff behind the breadbox and some remnants in the ac ducts. So I know it's a pain to remove the breadbox and the lower carpeted panel. I know what I have to do. I'll just have to take my time and deal with it. What I'm interested in is the actual dash removal. I see the upper corner nuts and the braces that go to the firewall on each side of the defrost duct, and the bolts on the trans tunnel. Enlighten me with your detailed knowledge of getting the dash out or is it just too much of a pain? I'm pretty familiar with working on the car but it's been awhile since I messed with the dash. Once removed, I want to soak it in my bathtub, along with all the other plastic parts, to clean and sanitize them including the ac/heating ducts. One time, long ago, I dismantled a C4 but don't recall everything I did years ago. Pic attached of the dismantle I did. BTW, the pic below is not the car I'm working on right now.

 

I may have to go to the local pic n pull. They have a couple of C4s that are completely thrashed. Maybe I can figure out how the dash comes out without breaking anything on my car to figure it out. I try to take some pics and post.

 

Well, I got to Pic n Pull. Both C4s had some of the dash pulled out, I say that loosely because some people prefer to rip good stuff off to get what they want. Anyway, I realized that it wasn't super hard to remove the dash but it is tedious. I'm going to try to detail the steps from memory since I just got done removing mine. The FSM does show the steps, I attached a pic from the FSM for reference. It's called the I/P carrier asm. I'm not going to go into every single detail since it would take forever. I would expect that anyone attempting this has some basic knowledge of the C4 interior. Because I had a mouse problem I decided to disconnect the battery and completely remove the interior including the seats, seat belt receivers, console door lid, console/shifter trim plate, console side panels, floor console assembly, all associated wiring, sill covers and all the carpet. So what I'm left with is the complete dash. Remove the two hush panels or IP insulator L & R aka under dash closeout panels, disconnect both foot well light connectors, the hood release bezel, remove the ALDL connector screws holding the bracket to the dash, remove the LH lower trim pad by removing the perimeter screws attaching the trim pad to the dash, remove the two larger screws through the lower carpeted area of the trim pad. Tilt the steering wheel down and remove the tilt lever then remove the two nuts holding the steering column to the support and lower the column. Remove the cluster bezel, center duct/heater/radio bezel, remove the LH and RH side dash to door seals, remove the RH fuse panel door and the side cover screws from the side of the dash, remove the inner LH and RH side duct to side dash screws, remove the upper, by the windshield, dash pad defroster vent screws (2) and the dash pad screws under the front leading edge of the dash, if you have speakers in the dash board then the wiring will need to be removed while pulling the dash pad straight out, remove the two aluminum brackets that attach the top of the dash to the firewall, remove the instrument cluster 7mm screws (4), unplug the connector(s) and set aside, remove the center info panel screws (3)?, pull the info panel toward you and unplug the large and small connectors, I have electronic AC controls so I removed the screws holding the controller, unplugged the connector and removed the controller, remove the radio screws and all plugs, behind the center info panel is a flasher, fuse panel, relays and connectors mounted to sliding partitions, other than the fuse panel detach all components and shove the wiring behind the dash towards the firewall, remove the two 10mm screws holding the lower center of the dash to the trans tunnel bracket, the screws are on the sides of the trans tunnel bracket, you don't have to remove the bracket nuts from the trans tunnel. You might want to take a break because the real fun is just beginning. One of the harder areas one will encounter will be the RH lower hush panel and breadbox removal. Remove the two 7mm screws holding the upper breadbox brackets to the dash, if you pull the breadbox away from the dash you can see two more brackets being held on from below with 7mm screws. These two lower screws pass through the hush panel plastic before they engage the J nuts on the bread box. You're going to need some 1/4" ratchets, extensions, swivels, and a 7mm socket to remove the two screws. Locate the duct from the center plenum to the breadbox vent, there is one 7mm screw holding this vent to the dash, remove this rearward facing screw, remove the duct and flexible conduit from the breadbox and remove it from the dash. I was able to remove RH side dash fuse panel by lifting the center lower center edge of the fuse panel with a screwdriver while pushing the lower end inward and detaching the upper edge which is just hooked onto the dash plastic. I turned the fuse panel sideways and push it rearward through the rectangular opening in the dash to access the nut on the lower trim pad. The lower trim pad studs pass through two vertical metal support braces and the 4 nuts must be removed in order to remove the dash from the car and to gain access to the lower breadbox screws. The upper left and right nuts of the trim pad are visible through the windshield and are fairly easy to reach through the top of the dash, a 3/8" ratchet, a 6" extension, a universal joint, and standard 13mm socket to remove the upper nuts from the trim pad, the far right hand lower nut can be accessed now that the center plenum to breadbox duct and fuse panel are out of the way. I did remove the small air duct 7 mm screws from below the trim pad to remove the duct and gain more room to push the wiring around to get to the nut. The inner lower nut is accessed from the top but the 6" extension is just barely long enough to reach the nut, if you add 1" extension to the 6" extension you should be good. Be careful not to bang the windshield with the ratchet, you don't want to break it. Once the trim panel is removed, you may need to pull and pry it down to remove it, you should be able to unscrew the PITA 7mm screws that's holding the lower edge of the bread box to the dash. The lower RH screw for the breadbox is accessible from the fuse panel side of the dash or from underneath like the LH screw, my RH lower screw was missing and I didn't check if it was accessible from below, hopefully it is. Now that you have the bread box and lower trim panel removed, whew, the job gets a little easier. A few notes to remember before trying to pull the dash, the dash is very fragile and excess bending or distorting might crack it. The dash is fastened to the car with two aluminum brackets on top of the dash held to the firewall with 7 mm screws, remove the screws and brackets, there are two upper dash nuts that are visible at the upper corners. There are two lower two nuts in the lower corners just above the visible lower edge on the A pillars. On mine, the lower corners are slotted so I didn't have to remove the nut entirely, the center of the dash is attached to the trans tunnel as mentioned before. Remove the headlight ****, there should be a slot in the plastic **** to push the metal clip on the shaft rearward or toward you to release the **** from the shaft, next I used a large screwdriver to engage one slot of the nut that's holding the headlight switch to the dash, some people use needle nose to catch the notches to turn it, the fog light switch will not pass through the plastic dash to remove the wire connector, I use a medium flat blade screwdriver to pry the sides of the connector tabs from the backside of the dash, a little tricky but doable. Just when you think it's ready to pull, something else gets in your way. If you look inside the LH dash duct you'll see two screws holding the duct to the dash, remove these two screws and separate the duct from the dash, this duct is held onto the dash with a 7mm screw. There is a smaller duct that is screwed to the side of the LH dash that delivers air to the door window defrost. Remove the 2 screws, below the cluster area this conduit is attached with a metal strap and a rivet, my main wiring harness was routed so that the dash would not just come out straightaway. Drill or grind the rivet away so the dash to door vent duct can be removed. Additionally, the main wiring harness is supported by a plastic conduit that is held to the dash with 7mm screws that must be removed, you can see the end of the screws going through the j nuts behind where the instrument cluster was. After I removed the wiring harness from the dash I was able to slide the dash to the right thereby allowing the disconnected dash duct to slip past the wiring harness. You'll see this when trying to remove the dash if the harness was routed the same as mine was. Other things to look out for is a plastic wiring harness retainer holding the wiring harness to the dash behind where the bread box was located. Some needle nose pliers or right angle needle nose pliers to squeeze the harness barb allowing it to pass through the hole is required. You may discover similar wire harness retainers elsewhere. Also, behind where the instrument cluster was located you may see the tips of several 7mm screws engaged in J nuts attached to the dash , you may need to reach behind the dash to remove these 7 mm screws to release whatever is holding the dash from being removed. Behind where the instrument cluster is located are various large rivets holding various things in place behind the dash. I didn't have to drill any of these out. Please keep in mind that I am posting all these steps from a 70 year old man's memory so I might have missed something. It may be helpful to have an assistant guide the dash past any brackets, wiring, or obstructions that are preventing the dash from being removed and without breaking this fragile piece of plastic. I looked all over the various forums looking for anything that would guide me in this process and found none. Sure I could make a video but I'm not good at that. If anyone has any questions about this then I can certainly follow up with your post. When I go to put it back together I may post some pics of the critical spots I encountered when I removed it. Thanks for reading/looking.

 

Nice reference and detail, it's appreciated... By dash skeleton, I'm assuming it's the plastic skeleton? Removal is very tedious for sure.

 

Yes, in the FSM it's the instrument panel carrier. What a flimsy, fragile piece it is.

 

Yes, I just edited the post and changed skeleton to dash. Makes more sense.