Thanks Richard. I appreciate the response. For the sake of clarity, I have a 2000 C4 Cab Tip with M490 and M680 installed. From an interior view, there is just the PCM with the tape deck and the Nav disk unit below. A/C controls are already located on the bottom due to the PCM and Nav consumption of real estate. I have not started disassembling anything.
If I can retain and use the factory amp for the time being, that is fantastic, maybe not for sound quality, but certainly for time, money, and personal preference reasons. My current plan is to leave the PCM1 in place, and put a single-DIN unit in place of the NAV controller (upper slot on lower console). I purchased the unit (Pioneer DEH-X8800BHS) from Crutchfield and it has been shipped with a Metra 70-1787 harness as well as an antenna adaptor.
After perusing the uploaded wiring diagram (borrowed from another thread…appears to be the correct one) and then comparing it to the wiring diagram for the Metra harness (unsure whether it could be posted here as the diagram is a Crutchfield product), in my layman’s point of view it would appear that with some slight modification, the harness should “connect” the radio to the amp in such a way as to function. However, I have read in several places that the amplifier is not compatible with aftermarket head units. The statements have been that generic, so I have no other details as to why at this time.
So in light of that, below are my assumptions as to the connections. If you wouldn’t mind giving them a onceover, it would be greatly appreciated.
1. Anti-theft connection will have to be disconnected and permanently insulated once the PCM1 is actually removed.
2. C1 Connector (Yellow)*
PIN 1: Rear Left (+) ---> connects to ---> Violet RCA on Red Metra Harness
PIN 2: Rear Right (+) ---> connects to ---> Green RCA on Red Metra Harness
PIN 3: Ground (-) ---> connects to ---> Black wire on Red Metra Harness
PIN 4: Front Left (+) ---> connects to ---> Gray RCA on Red Metra Harness
PIN 5: Front Right (+) ---> connects to ---> White RCA on Red Metra Harness
PIN 6: 12V+ Switched ---> connects to ---> Blue and white wire on Red Metra Harness
3. A Connector (Black)*
PIN 1: Unassigned (normally speedometer but not with M680 installed)
PIN 2: Unassigned
PIN 3: Unassigned (no phone prep on my car)
PIN 4: Terminal 30 (12V+) ---> connects to ---> Red wire on Black Metra Harness
PIN 5: Antenna Booster ---> connects to ---> Blue wire on Black Metra Harness
PIN 6: Terminal 58d** ---> connects to ---> Orange wire on Black Metra Harness
PIN 7: Ignition Lock, Terminal 86s ---> connects to ---> Yellow wire on Black Metra Harness
PIN 8: Terminal 31 ((-) Ground) ---> connects to ---> Black Wire on Black Metra Harness
*Crutchfield wiring instruction for Metra harness indicates yellow and red wire functions are reversed on my model year. Colors listed above to match correct pinout using that assumption.
**Not entirely sure what this is…labeled as illumination on Metra Wiring Diagram
Thanks again for the help. Hoping this is all that is necessary for the moment. I drive my car A LOT, and the added features of the new head unit would be most welcome.
996_Group_9_Circuit_Diagrams_Part_1 Radio.pdf