View Full Version : signal ground wire to speaker wires

05-25-2013, 02:37 AM
:eek4dance:The harness I am using has the signal ground wire connected to the speaker wires. Is this so it won't pick up that whining noise from the engine?
I tried to research this on the Internet, but all the browser does is take me to web sites where they try to sell me something or useless information that has nothing to do with what I am looking for. Has anyone noticed this happening lately?:evil:

05-25-2013, 04:05 AM

05-25-2013, 05:15 AM
If you're talking about a System 10 harness that retains the factory amplifier, it's because the amplifier needs the ground from the signal source. So it's an exact duplication of the factory set up with an aftermarket head unit.

05-25-2013, 07:55 AM
Ya, this was one of those MR2 PC9-406 SmartLead adaptor that I bought from jolly old England. Has anyone used one of this to hook up an aftermarket system to their '90 Celica System 10 factory harness. This is the one that has 14 pins, and the cd and cassette are in 2 sections.

05-25-2013, 04:56 PM
I considered it... but between paying $40+ for an adapter that should be $10-15 tops, and the fact that I picked up an Alpine five channel for less than $300 made me decide to just go the full replacement with new wires on my car (91 GTS, should probably document the actual work more... but that requires being home to work on it.

05-26-2013, 01:54 AM
I actually got it a couple of years ago but am revisiting it now. I noticed on the Smartlead the coresponding wire for turning on and off the amp on the original connecion is a wire with a bullet connector on the Smartlead. Shouldn't I splice that lead into the one that turns on the power antenna?

05-31-2013, 06:12 AM
Check the Audio and Electrical section for my write up on the System 10 install. It should answer most of your questions.