Bypassing the factory S14 stereo amps

[AZhitman]

I recently purchased a ’95 SE with a malfunctioning OEM Clarion CD stereo (the front speaker amp was dead). No problem, I thought – bought a Kenwood stereo and a wiring adaptor for ’95 and up Nissans ($7 at Wal-mart), connected everything up, and…nothing.

Not good.

The first issue I ran into was that the SE model uses a diversity antenna setup (one in the rear glass as well as the usual power rear antenna) with a non-standard two prong plug. Additionally, the system is wired to use the antenna as the ground, so it has to be hooked up in order for the system to power up. Fortunately, an adapter exists that plugs into the standard antenna receptacle ($12 at a local stereo chain). So, I hooked up the adapter, and…nothing.

The ’95+ SE (as well as other Nissan/Infiniti models of the same era) uses a system with remote mounted amps – in this case, under the rear package shelf. If you want to avoid re-wiring all six OEM speakers, these have to be disconnected and bypassed. The problem is that they are connected to the rest of the system by two plugs containing a total of twenty wires.

Again, no problem, right? – just find a wiring diagram. Good luck. An extensive search did turn up a copy of the European S14 factory service manual…but the Euro version apparently didn’t offer the CD system – at least, it wasn’t documented in the manual. Bought the appropriate Chilton manual for the car, but the wiring diagrams it included were too high level to be of any use.

My research had allowed me to identify about half of the amp wires, but trial-and-error connecting had resulted only in blown fuses and the triggering of the “Check Engine” light ($90 to have the codes read, diagnosed, and cleared).

I decided as a last resort to remove the OEM amps, take them apart, and see if I could figure out which wire went where. Salvation! Turns out that Clarion has thoughtfully marked the circuit board in each amp with the function of each wire (in English, no less!). So, to prevent other S14 SE model owners from going through this little “challenge”, I have shown below the layout of the connector wires, and a “map” to show what to splice to what:



1 Blue left front speaker neg. input

2 Black right front speaker pos. input

3 Blue/yellow left front speaker neg. output

4 Brown/white right front speaker neg. output

5 Brown right front speaker pos. output

6 Pink left front speaker pos. input

7 White right front speaker neg. input

8 Blue/white left front speaker pos. output

9 Blue acc.

10 Green/red on/off

11 Purple left rear speaker neg. input

12 Pink right rear speaker neg. input

13 Green left rear speaker neg. output

14 Pink right rear speaker neg. output

15 Blue right rear speaker pos. output

16 Green left rear speaker pos. input

17 Blue right rear speaker pos. input

18 Red left rear speaker pos. output

19 Blue acc

20 Green/red on/off

Splices:

1 to 3

2 to 5

4 to 7

6 to 8

11 to 13

12 to 14

15 to 17

16 to 18

It will be noted that the above scheme leaves out four wires – the two “acc” and the two “on/off” wires. No combination of connections or grounding of these wires powered up the stereo, so I ran a new switched power wire from the fuse block to the stereo (red wire). Stereo works, antenna works, no popping fuses or flashing lights.

Good luck!