Originally Posted by Bolamite

Here it is people, YES YOU CAN ADD NAV TO A NON NAV CAR, and heres how.
Special thanks to Paul Mooney, the resident Nav guru, and Acura North Scottsdale.
Before I start I gotta say, this project is not that hard if you have some audio video experience and know how to read a wiring diagram. I'm only gonna DIY the stuff thats directly related to the nav, you can get instructions for taking your console and dash apart from lots of places. This is for a 1999 TL-P and there are some differences in the model years but nothing big.
PARTS LIST:
Nav Display and DVD unit $????EBAY
Instrument Cluster Bezel $90
Left and Right Brackets for Nav Display,EQ, and Radio $20
Gps Antenna $115
Climate control unit (2 pieces) $115+$135
Hazard Light Switch $25
Bracket for Nav DVD unit $25
Wire: My Nav unit and display came with the cut off connectors so I just soldered wires to make a harness. I used about 15ft to run from trunk to dash, I recommend you use 17ft. If you can read a wiring diagram you'll know what you need to get. Read the whole DIY before you start so you know where all the wires go when you buy them. The only wires I didnt use were the Nav service connector and Alternator charging signal. I used 22 gauge for everything. I got 2 and 4 conductor/stranded/shielded wire from home depot for about 15 cents a foot, they also have primary wire. You dont have to shield everything so get some primary wire too. I recommend you ground your shields exactly where the diagram says, ESPECIALLY if it grounds to a pin in the module, better safe than sorry.
MAKE A WIRING DIAGRAM of your homemade harness so you dont get lost DONT SKIP THIS, YOU WILL BE SORRY IF YOU DO
Zip ties
Electrical tape
Theres also various screws and such, check out Paul Mooneys siteHERE for a parts diagram and you should be able to figure out what you need.
TOOLS:
Ratchet
Dykes(cutter)
Basic metric socket set
Philips Screwdriver
Set of Torx drivers or bits
Soldering tools
Multimeter
WIRING DIAGRAMS
Razor or wire stripper
Eyeglass screwdriver set will help you pull the pins out of the connectors.
First you need to take out your back seat. Pull up on the front edge of the seat itself and it should pop up, then you need to undo a 10mm bolt thats holds the seat in. Its in the middle/left between the seat and seatback. Pull the seatback up and out and you'll be looking at this.
Next remove the cover for the sub. For those of you who aren't familiar with removing trim pieces, it usually is just pulling firmly but gently on the piece and working it out. Remove the piece of trim on the left of it(drivers side is always left)and mount the GPS antenna like this
Make sure you run the wire through that hole so you can connect it to the Nav unit. Mount the Nav unit in the trunk so you can judge where to run the wiresThen pull the trunk carpet trim back so you can run the wires Now take apart your passenger side sill trim front and back. Just pull it up gently and the clips will release, dont worry if the clips break, do worry if the trim breaks. Run your wiring harness behind the backseat and down the passenger side of the car, but first separate the Nav units ground, ILL and Back Lt and run those behind the left side of the trunk trim and splice them to the trailer lighting connector which has an ILL, and Back Lt circut and a Body ground right below it.Then separate the Nav unit ACC and run it to the middle of the backseat and use a coat hanger to slide it under the carpet so you can splice it to the ACC power in the center console.Make sure that you go behind the seatbelts and secure your harness to the harness thats already running down the passenger side with zip ties. Pull back the carpet and run the wires under the passenger footwell and up to the dash.
Now you need to do some splicing. The 99 uses a vsp sensor which only comes on Nav vehicles and only in 99, just splice your PCM speed signal instead. Your PCM is behind the radio on the floor and the front most connector is the one with the speed signal. Use wire color to make sure you have the right wire before you splice. The rest of the wires go behind the radio and display. When you take out the radio you need to take out the EQ and brackets because the new brackets will have nuts on the back to hold the bolts which mount the Nav screen. Thats the only difference in the brackets but it is very important so make sure you have the nav brackets. Take out the stupid CD/WTF is this/waste of space thing above the radio so you can put the new climate control unit in. All the connectors will plug in to the new stuff (climate, hazard) but the clock goes byebye. Use the clock wires for B+ for the Display and Nav unit, ground, ILL+and - for the display, and ACC for the Display. You need to put a 10 amp fuse in the clock circuit or it will just blow the 7.5 it has(passenger side fuse box). For the security signal cut into the radio and add the Nav display in series to the circuit so the signal goes through the nav display instead of straight to the multiplex unit. Pin A4 of the radio, you'll see what I mean. For the voice into the radio you should have 4 empty pins in the main radio connector. I went to Best Buy and bought a reverse wiring harness so I could get the pins to fill the slots, part #71-1721 I think. Make sure its the same connector that goes into the back of the radio. To get the pins out you need to pop open the little clip on the connector then use something VERY small, like a sewing needle, to lift the tab inside of the connector and pull out the wire. This is pretty hard to do if you dont know how but dont get frustrated, if you insert the needle into the front of the connector you can get it underneath the tab which holds the pin in and lift it enough to slide the pin out. Dont pull on the wire until you lift the tab because it will just get stuck. Once you have the pins out you can connect them to your harness and plug them into the radio connector, make sure you use 2big and 2small pins and put them in the right place. Run the wires to the appropriate place and put your car back together. Remember to check your system BEFORE you put it back together and dont forget to hook up the EQ when you test or you wont get sound from your radio Im sure I forgot something so if theres any Q's
HOLLA