kmn5

ARHHHHH!!!! What a headache!

I'm wiring up an aftermarket head unit (also a pioneer)
in my sc300. I took out the factory amp under the CD changer and was proceeding to jump the speaker + wires (SINCE the AMP has BEEN DELETED) and I find out that the factory wiring speaker harness from the HU to the AMP is SINGLE negative wire, A common negative for all the speakers! I've never seen a setup like this, I do know my new head unit CAN'T use a common Negative wire. It says so in the installation manual.


SO, my only choices now is to:
1) Buy a new 4 channel amp and run RCA wires from the new head unit to the trunk, and then output the singal into the speaker wire harness. SInce the amp will provide both positive and negative singal for all the speakers. The drawback is that my head unit has a built in amp with 200 watts! , It'll be a waste not to use it

2) Run Four separate Negative speaker singals from the headunit all the way back to the trunk to where the speaker harness can accept the signal .
And use the Exiisting four positive speaker wire signals already in place from the HU to the trunk.


Us there any device I can add to the single common negative wire that will properly split it into 4 negative signals without messing up the head unit???

any suggestions??
thanks!
Ken

kmn5

just an update for those that may have the same question later on.

I tried using the standard SINGLE negative speaker wire to test. And it did work, but the sound had very very slight noise when music played quiet sections.

SO I just RAN FOUR new Negative speaker wires from the new headunit to the old stock amp location.

System sounds great now, with no noise at all, sound is very very clean and clear.

Ken

Seattle SCone

Glad to hear it worked out. When read your first note I was envisioning a common, grounded "negative" lead being connected to a "high power" head unit. Those typically need both speaker leads to be isolated from ground or else the amplifier output transistors go into overcurrent and burn themselves out, sometimes with a very loud bang as the casing blows. That trial with just the single negative wire might have been the end if Lexus had also grounded that "negative" wire.

Thankfully, your head end lived through the experiment and you've now got the proper wire runs. You probably want beefier speaker wires anyway if you are expecting the head end to power the speakers.