QuestionI am installing a hidden stereo system in a 71 Monte Carlo SS. The original wiring harness seems to run a single negative wire to the front speakers and a single negative wire to the back speakers, then separate positive wires to each of the four speakers. I’m trying to use the existing wiring harness and tie in at the radio. All negative speaker wires are( or appear to be tied together at the radio). To do this I was planning on tying to the negative speaker wire at the existing radio and running a speaker ground to the new unit and tieing all speaker grounds at one place. The new unit has separate grounds for each speaker. Do I have to rewire all the speakers with separate grounds? Any harm in tying them together?
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AnswerSkip, sorry for the delay in answering. Life is pretty busy! =]
Since you are building a "sleeper", I'm assuming you are going for a good quality sound. The common ground circuits are very faulty and can yield excess noise, especially with an aftermarket radio. On some of the older vehicles, there are either stock amps, faders, outboard EQs, etc. that will cause serious problems if you install any MOSFET powered units.
Unfortunately, in order for the best quality of sound and install, your best bet would be to run new wires to the speakers, but it's not 100% necessary.
If this is an undesired option, you can make an attempt to split the ground harness accordingly and check for continuity between the radio and speaker pods to identify which speakers each wire corresponds to. You will also have to verify the circuit is supporting AC voltage from the radio to each speaker, or tone test it once it's all wired up. Worst case scenario, you'll have to run a few wires which shouldn't take very long if you know your car very well.
Hopefully this helps. I'm not sure if you're building for show or for daily driving, but either way will work. I tend to take the road less traveled for better quality. =]
If you need anything else or need better explanations, let me know.
