meatwad Posted December 31, 2023 Share Posted December 31, 2023 Hi all, I have installed an aftermarket headunit (Atoto F7) in my 1999 LE with Bose factory amp using Scosche harness # NN07B. This harness is supposedly specifically for factory amplified Nissan systems. The wiring was fairly straightforward and the unit gets power, but no audio is delivered to the speakers. I suspect this is an amp issue (not powering on?) but I’m completely lost on how to go about fixing it. Also, there are two separate wires for ground on the Scosche harness. There is a chassis ground (black) and amp ground (black + white). I have tried connecting each of these independently to the ground wire (black) from the headunit and still, power but no sound. I must be missing something. I’m admittedly a complete noob when it comes to car audio so any advice would help. Thank you Link to comment Share on other sites More sharing options...
meatwad Posted January 1 Author Share Posted January 1 Update: I spliced the amp turn on wire (blue + white) in with the red ACC wire to ensure power is being delivered to the amp. I can hear a slight pop and a continuous quiet hum while touching the wires together so I’m assuming the amp is receiving power. Why it’s not putting out sound is beyond me Link to comment Share on other sites More sharing options...
Slartibartfast Posted January 1 Share Posted January 1 I see that your head unit and adapter connect using RCA plugs. I haven't set up a head unit like that, but the first thing I'd do is poke around in the owner's manual to see if there's some some setting you need to change to switch it over from the internal amplifier to the RCA outputs. I would also double-check that the RCAs are plugged into the correct holes--looks like you want the four closest to the power plug on the back. If it's not that easy, check fuse #4 (15A), in fuse box JB (looks like that's the one under the dash). That's the unswitched power feed for the audio system, and while the head unit may power up without it (it also gets power from the ignition switch), the audio amps (there are actually three of the little blighters) will not. If that fuse is blown, check your work, because fuses usually blow for a reason. Check your color code match-ups, look for damaged insulation/slipped-off heat shrink, make sure the pins aren't folded over in the adapter plugs, and make sure you didn't pinch a wire when you bolted the radio back in. If the fuse is good, and you test from the yellow wire in the head unit plug to ground, and you should see around 12v whether the key is on or off. The only other thing I see that could take out all the amps at once is the turn-on signal from the head unit, the one you mention in your second post. It should be blue/white coming out of the head unit. Confirm that this connects to the light green/red wire in the harness, and confirm that it tests at +12v when the head unit is trying to play music. If that checks out, I would try and track down the relay for the front speakers to confirm that it clicks when the radio turns on and off, or find the rear amp and verify that it's getting signal to the appropriate pin. The circuit diagram for the Bose audio system is on EL-145 of the '99 manual (download it from Nicoclub if you haven't yet). 2 Link to comment Share on other sites More sharing options...
meatwad Posted January 4 Author Share Posted January 4 Fixed! Turns out I’m just stupid. Slartibartfast had the correct solution with the RCA plugs. I was confused because the stereo I set up before did not use them (despite having a factory amp) and they are not colour coordinated to the proper female ports on the headunit. I plugged them into the RL, FL, RR, and RL ports then used the balance/fader while playing music to determine which plug corresponds with which port since it isn’t labelled. Often times the correct solution is the most simple or easiest overlooked… Thank you Slarti! 2 Link to comment Share on other sites More sharing options...
CamperDan Posted January 5 Share Posted January 5 18 hours ago, meatwad said: Fixed! Turns out I’m just stupid. Slartibartfast had the correct solution with the RCA plugs. I was confused because the stereo I set up before did not use them (despite having a factory amp) and they are not colour coordinated to the proper female ports on the headunit. I plugged them into the RL, FL, RR, and RL ports then used the balance/fader while playing music to determine which plug corresponds with which port since it isn’t labelled. Often times the correct solution is the most simple or easiest overlooked… Thank you Slarti! That's so awesome, basic trouble shooting for the win. I always say when in doubt look again. Glad you you were able to figure this out and now you can enjoy having music in your R50 once again. Chris. 1 Link to comment Share on other sites More sharing options...
Slartibartfast Posted January 7 Share Posted January 7 Nice when it's the simple fix! Good thinking using the fader to work out which output was which. 1 Link to comment Share on other sites More sharing options...
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