Since my own thread got dugged up I figure I'll post some comments on my own experience. A few years ago I went through hell and back trying to install an aftermarket stereo in my 1998 Deville but I've got it figured out. Like what BigOLak said the main issue is the data bus, the two purple wires on the back of the factory needs to stay hooked up. I took pictures while I did this so here they are.


Here's the beginning...I relocated the factory radio under because the wire loom is long enough and at the time I wasn't sure if this is how I solve the sleep mode issue. Instead of tapping into my ignition wire I ran a separate 12v wire to a SPST switch to turn my headunit on and off, this way I can have my stereo on without the keys at all. It's kind of more convenient but just make sure to turn it off when you park the car. I also ran separate power/ground wires(the 8 gauge wire in the picture) for my headunit, that way I can tap more 12v stuff to it such as TVs, active crossovers, etc. without worrying about the factory wiring.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0735.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0933.jpg


I used this as the power wire entry, because I didn't feel like putting a 1" hole in my firewall

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0719.jpg


I planned on having a massive stereo system so I used 0 gauge wire. The red 8 gauge is for the headunit. You'll have to remove the metal plate above the battery.


http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0721.jpg


Later on I added a chassis ground to improve current flow


http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0955.jpg

NOW TO THE IMPORTANT STUFF :want: This is the factory wiring harness, see those two purple wires? That's the databus line we're talking about. The green-to-red wire is the radio antenna trigger.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0734.jpg


Later in the years I extended the wires and relocated the factory radio into the top right corner of my trunk. I went to a junk yard and got the guy to cut off a factory radio harness, I extended the two purple databus wires, the power/ground wire and two other wires that I can' remember(sorry). Put it face up so it doesn't get turned on again. I added some cotton padding so it doesn't bounce around.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0938.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0944.jpg

Pull up on the stepper and it should just pop off, there are tons of room for big wires.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0346.jpg


To anyone who may be concerned about side airbags, there are no electronics attached to the door cover besides the factory tweeter, which I replaced with JBL then later Pioneer Premier units. There's one screw behind the red/white bottom door light and one under the power window switches, use a plastic pryer to pry them out. Be careful because if you break the tabs it won't seat right anymore. The power doorlock just pops out and you can also loosen the triangle sideview mirror piece by pulling it lightly. All the wires to the switches are quick-disconnects. Pull the door up once you remove the screws. I have no problem fitting in 5 1/4" woofers from JBL and Pioneer Premier.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0732.jpg


I also made some fiberglass pods for my rear passengers because to be honest the factory door location is terrible. I'm going to do the same for the front eventually.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0430.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0429.jpg

As far as removing the rearseats, push the bottom part against the rear and you should be able to lift it off. They're hooked onto the bottom like many other cars.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0940.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0949.jpg


Now to remove the top half there are four bolts...two on the bottom and two on the top but the top ones are on the opposite side so you'll have to crawl into the trunk to get to it. The bottom bolts also holds the seatbelts so remember to tighten them after you're done! The carpet cover behind the backseat are held together by four little plastic screws under the rear deck, you can just pull them off.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_1042.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0728.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0951.jpg


Once you loosen the top screws the fuse rack will be halfway dangling, so you might as well take that off while working on the wires.

Editing

The 3rd brake light cover can be removed by pulling it towards you.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0945.jpg


To remove the top carpeted cover to gain access to the rear 6x9 holes, you'll have to pop off this little tiny plastic bolt...it was a real pain for some reason.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0947.jpg


Hummmm found some factory paint spill :suspect:

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0948.jpg


Right now is a good time to add some dampening material too, I used an off-brand but to be honest Dynamat is a better product.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0952.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0731.jpg

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0730.jpg

This is with the fuse rack back on.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0941.jpg


The little box in the red circle is your remote lock receiver. It has a little metal tab on the opposite side as an antenna. You'll notice a better range for your remote lock if you extend this "antenna" with some thin 18~22 gauge wire, like a foot to left and right.

http://i82.photobucket.com/albums/j255/weister42/1998%20Cadillac%20Deville%20Stereo%20Install/IMG_0942remote.jpg

I've gone through a few different speaker/amplifier/subwoofer/headunit setups since I did the install but one thing for sure is I never have any problems with sleep mode after that, and being able to turn the stereo on without the keys has been more of a blessing than inconvenience. The stereo imaging in the backseat is amazing and all of my friends who listened to it said they want it.


Do feel free to ask me any questions concerning this model year of Devilles, no one needs to be put through all the wrong conclusions and growing white hairs that I had to deal with.

Also what's with the short editing time??? I can't even go back to correct some spelling :)

This thread should be a sticky. ;)

Right on, if people find my information useful then make it a stickie :thumbsup:

this looks GREAT. can you email this to me and/or contact me so that i can get some help with the install? :thepan:

i have a 1999 deville and i am going to put a system in it. need to make sure that i avoid the databus issue. please, please, PLEASE help me out!!! ive been reading that the wiring harness, the gmrc-03, is not the solution and before i remove my factory deck, i want to make sure that i dont have any problems with my system.

i am installing:

1 - clarion vz709 touchscreen deck
2 - boston accoustic 12" subs
2 - pioneer premiere 6x9's
2 - pioneer premiere 5.25's
1 - tv in each headrest
1 - viper 5901 car alarm
1 - mtx 4 channel amp for highs
1 - mtx mono block amp for subs
1 - capacitor
1 - gel cell battery to run system

did you have to extend the entire harness to the trunk or just the two data bus wires?? Thanks, Dan

did you have to extend the entire harness to the trunk or just the two data bus wires?? Thanks, Dan

i was wondering the same thing. however, i'm guessing that you're going to need some sort of power running to the original head unit.

another question regarding the very first photo. when you initially had just that setup with the original head unit sitting below the aftermarket, did the system work like you wanted it to? did you simply splice the speaker wires, etc, and run the original harness to the original head unit?

i have completed my install and will post pics if anyone wants/needs me to do so. i spoke to metra (maker of the wire harness) and they advised that if you run a constant 12v line to the system and a constant 12v power line to the alarm (databus 2) you will avoid this problem. my system has been in since august and no problems thus far.

i have completed my install and will post pics if anyone wants/needs me to do so. i spoke to metra (maker of the wire harness) and they advised that if you run a constant 12v line to the system and a constant 12v power line to the alarm (databus 2) you will avoid this problem. my system has been in since august and no problems thus far.


Post them up! I encourage everyone to post pics of their installs, preferably in one thread to keep it organized. Maybe a sticky with all the forum users system pics? I think it would be helpful to others thinking about doing their own installs.

nice well done i like the 5.25 speaker coponet relocation thinking of doing it in my deville.. so did you have to take the whole side panel out to cut ot the circles or was it the seats .

I just installed my new HU in my 1999 Deville yesterday. Thanks to this forum everything went well. The E6 and F6 data cables for the old HU I ran to the trunk and used the 12v power and ground that was used for the disc changer to supply power to it. I didn't use a harness just pulled the E6 and F6 pins out of the harness and hooked them up in the correct male pins on the old HU, which I have discretely hidden next to my spare tire. Would never guess it's there. So for the record, the only 4 wires that need to be ran to the old HU are 12v power, ground, E6, and F6. That's it, no sleep mode, no alarm problems. And for the retained accessory power (RAP) I spliced into the front passengers 12v window power. To figure out which wire to splice into pop up the panel on the door that has the window up/down switch and see what color the wire is. Then snap that piece back on and find that wire in bundle that is on the far right side of the passenger side (around the same place you would placing all your new wiring for that is routed to the trunk). Make sure that the color wire for the window up/down switch is the only one in the bundle. Splice it and run a new wire from there to your new HU. Now you should have the RAP 10 minute or until a door is open feature.