How-to repair 97 Deville inop nstrument Panel Cluster

Thanks to Nick93SDV on cadillacforums.com this how to write up as well as related photos can be found at;
https://www.cadillacforums.com/forums/cadillac-tech-tips-how-fix/239928-instructions-fix-blanked-out-instrument-panel.html

Instructions to fix a blanked out Instrument Panel Cluster display on a 97 Deville

    For those of you who are facing the same problem I had with the center display on the Instrument Panel Cluster (IPC) on my 1997 Deville, the steps below describe how I fixed it today. In my car, the center display (defined here as the displays for speed, fuel level, trip, shift position, total mileage, turn signal indicator, and the Driver Information Center message readout) went blank. Idiot lights along the top of the IPC (parking brake, SES, airbag, etc.) were fine, as were the climate control display and the fuel economy and range display.

    After searching the forum archives, I could see that there were three low cost ways to go when the center display blanks out. One is to remove the IPC unit and send it to a company like BBA Remanufacturing (they advertise their service on eBay). For $120 all in, they give you pre-paid mailing labels to send it to them via UPS ground, they do the repair, and then ship it back to you. This has a lot of upside because if there are a number of unknown things wrong with the IPC, they can fix them all (this is what I would do if more than the center display was out on the IPC). Downside is the cost and the fact that your car will be DOA for maybe 2 weeks depending on shipping time. The second is to buy a used IPC on eBay or pull one at a junk yard and swap the entire unit. Problem here is the fact that in the late 90s Devilles, at least, there is a lot of stuff stored in part of the IPC, such as odometer and key resistor values. A Delco shop would be required to reset the replacement IPC prior to installation to be compatible with other on-board data stored by the PZM, etc. The Factory Service Manual (FSM) describes how one programs the IPC after installation using three cycles of 10 minute “on” periods, but I believe that is just to "teach" the IPC after Delco has already put it into “learn” mode. I have no idea how much Delco would charge for this but it can’t be cheap. The third is to get a used IPC and split it in half, installing only the display portion into the original IPC. The brains in the IPC are located in the back portion, so a display swap means that you don’t have to worry about odometer memory or other similar stuff. That’s what I did.

    Total cost was $59, the price of a used IPC I got through “boofishnp” on eBay (fast shipping by the way and a 30 day guarantee, which was nice). It took me about 2 hours total to do this, but it would have been a lot faster if I knew what I was doing in advance.

    1) Buy a used but working IPC for the right model and year.

    2) Crack open a beer. You might need two more for the whole job. In fact, put a six pack on ice.

    3) Disconnect the ground to the battery (8 mm. wrench). FSM says to simply pull the “A5-IPC (Ign)” and “B5-IPC (Batt)” fuses from the trunk fuse panel and the “A3-IGN1” fuse from the engine compartment panel but I’ve never been able to figure out how such terminology maps into what is actually used on the panel faces. Go clean your hands because this is the last time you really get dirty and you don’t want to smear grease over the interior like I did.

    4) We’re going to pull off the top of the dashboard. First, pry up the long defroster grill that sits by the base of the windshield. Mine was already loose but you might have to use a small flat head screwdriver.

    5) There will be two sensors attached to the defroster grill. Reach underneath and twist them counter clockwise and pull out of the grill.

    6) Remove three screws now exposed after the defroster grill is out. They have a hex head so I used a 7mm socket on a socket driver.

    7) This will probably be the hardest part of the entire operation. You are going to remove the front panel A\C-heat vent louvers (the things you move to direct the flow of air up or down, right or left). I started out thinking it was the entire A\C-heat vent that was being removed (which would include the wheel that shuts off air flow) but in fact it’s just the inside louvers which are in a single removable unit (the rest of the vent, including the wheel part, stays in the dash). You are going to need to use two very small flat head screwdrivers to pull the four units (one by the doors on each side and two in the middle vents cluster). Starting with the driver’s side, take a flashlight and look inside the vent. About a half inch in on either side of the opening, you’ll see a little U-shaped cutout that surrounds a tab used to lock the louver unit in place. Move the louvers around to get a better view if you don’t see it at first. What you need to do is to take one of the screwdrivers, push the blade into the cutout, and pry the tab out a bit. I found that if you push the screwdriver in a bit after the tab is pried out, it’ll keep open. While it’s open, use the other screwdriver to pry out the tab on the other side of the louver unit. At this point, you should be able to gently pull out the unit by the louvers. If it doesn’t come, you need to make sure the tabs are pulled out on both sides. I actually wound up snapping a couple of tabs until I got the feel of it but they aren’t all that important. Lay the removed unit somewhere out of the way so you can remember the orientation of how they came out. Repeat with the remaining three units. Drink another beer because you are about a third of the way through now.

    8) Remove the four screws that are now exposed after the louver units have been pulled, one behind each unit. It’s the same 7mm head. They are up and in, and a little awkward to get to. I found that having a magnet handy was a good idea, because I repeatedly dropped them into a hole when they were finally freed.

    9) Remove the big upper part of the dashboard. The FSM says that for Devilles you need to press down on the forward edge of the panel on the passenger’s side while pulling upward and backward on the rear edge of the panel on the driver’s side. I don’t remember this being necessary; I just lifted up and then worked the big sucker out.

    10) You’ll now see three electrical connection plugs to the IPC. Two on the upper left side, one on the upper right side. To pull them you will need to pinch the tabs on either side of the connector, and then rock the plugs out. If they won’t budge, make sure you have pinched hard enough because one of the tabs is actually the end of a little lever that locks the male plug into the female receptor. I don’t think you will confuse the location of these plugs on installation but you might want to make sure you know where they will go back in.

    11) There are four 7mm head screws holding the IPC in place. They should be obvious.

    12) At this pointy I simply pulled the IPC up out of the dash. The FSM says that the steering column opening bracket has to be removed first but that wasn’t an issue at all. I can’t see why that would make a difference anyway.

    13) Have another beer as you walk into the house with the IPC to do the transplant.

    14) Place the IPC on the kitchen table with the display pointing up. Using a T-10 torx bit (AKA “star bit”; a small socket would work too), remove the five screws holding the face panel and plastic lens to the IPC. Lift it off.

    15) There is a small display unit for the gas mileage\range display on the left and a similar unit for the climate control settings on the right. Each has a connector plug. To remove the plugs, you just push on the two little latches on either end of the connector. The end of each latch hooks over the plug, which is why they won’t come out. When you move the latches, the plug is pushed forward. Very clever. Why aren’t they all like this?

    16) Pull each of the small display units out. They come out very easily. Put them aside in the right orientation.

    17) There is a big electrical plug on the right of the main center display. Unlatch that like you did for the small displays.

    18) You will now see four screws with T-10 torx heads underneath where the small display units were. Remove them.

    19) Lift out main center display from the IPC.

    20) Repeat steps 14 to 19 on the IPC you got on eBay (or in the junk yard).

    21) Clean the dust off of the eBay center display and drop it into the original IPC. From this point on you will only be working on the original IPC but with the eBay center display. The rest (eBay IPC and non-working original center display) can be pitched but if you are like me, toss it into the ever expanding junk parts bin in the garage. You may never ever need anything off of this but can you take that chance? I don't think so.

    22) Reconnect the big electrical plug on the right where it connects into the center display. Make sure the latches have locked into place.

    23) Put the four T-10 torx screws back in that hold the center display to the IPC.

    24) Drop the two small display units back into their correct spots in the IPC.

    25) Reconnect the plugs to the small display units. Make sure the latches have locked into place.

    26) Clean the dust off of the inside of the face panel and drop it back into place. Secure it with the five T-10 torx screws.

    27) Have another beer as you walk back out to the driveway. You are two-thirds of the way through.

    28) Drop the IPC back into place in the dash. Again, I didn’t have to muck with the steering column opening bracket. It just dropped into the right spot.

    29) Secure the IPC into place using the four 7mm head screws.

    30) Reconnect the three main plugs into the IPC. You’ll have to pinch the tabs to open the little latch. Make sure they have snapped into place and are locked in.

    31) Work the upper part of the dashboard into place, making sure that those two sensors are through or at least near the defroster vent so you can pull them up and out later. I found that getting the driver’s side seated first then pushing the passenger’s side into place next worked best.

    32) Secure the upper dash using those four 7mm head screws you took out of the vents. I found that magnetizing the socket driver helped keep the screws in place until I was able to begin driving them in.

    33) Push the louver units into place. You should hear a faint snap when the tabs lock in but if not, don’t worry about it. The units only go in one way so if you can’t get them flush, try a different orientation.

    34) Secure the upper dash using those three 7mm head screws you took out of the defroster vent.

    35) Reinsert the two sensors into the defroster vent grill. The bulb-like one goes on the right. They lock into place when you twist clockwise.

    36) Push the defroster grille back into place. Mine never really snapped in but it’s been loose since I bought the car years ago.

    37) Reconnect the battery ground (8mm wrench).

    38) Start the car and look at your beautifully lit display. Drink another beer to celebrate.


    Hope this is useful…


    Nick in Palm Springs