3 Speakers stopped working and it's got me bloody stumped!

[jschw00]

Hey guys, I've got a 2005 gu that I bought ~12 months ago, when I bought it none of the speakers were working, I ended up putting 4 new speakers in and we were all good! I also put in a new pioneer headunit using plug and play adaptors to the genuine nissan harness, was fine for months and then suddenly 3 speakers stop and I only have sound through my LHF speaker. I have removed the doorcards and measured voltage to my lhf speaker and was getting 5.8-5.9v fluctuating between that, I measured the other 3 and they were all the same, Grounds all ok. I rotated the other 3 speakers that werent working through the lhf and they all worked fine. I thought maybe it was a headunit fault so tested it with another known working headunit and different plug and play adaptors to genuine harness and they still didnt work. My next idea was to run new speaker wiring but I imagine if they're all getting equal power as the working LHF, speaker wiring is okay. Anyone get any ideas? Cheers

[Hodge]

Hey mate welcome to the forum mate.
While you're sorting it all out, I'd suggested upgrading the speaker cables with some proper wire, even if it wasnt at fault. The factory speaker wire is woeful and upgrading the unit and/or speakers will be bottlenecked by the shitty wire.

[BrazilianY60]

Check for shorts close to the speakers. Most headunits isolate the shorted channels to protect the internal amp circuit. For example, if you bench test your HU with your speakers out of the car, possibly all four channels and four speakers would be good. With HU and speakers crossed out of your troubleshooting list, start looking for the shorts on the OEM wiring.