J_wings24 said:
Good stuff Keezer, I'll work on it this weekend & see if i can isolate the noise.
One thing i just thought about, When I'm listening to the radio, park the truck & turn it off I have perfect reception. the noise is tied to the engine running.
I'll keep you posted,
joel
The majority of noise comes from your alternator and ignition, but Toyota knows that and so from the factory they are usually fine. What happens is things age and people replace stuff.
I'll go on a limb and say you don't run factory Denso spark plug wires. Toyota uses carbon core resistance wires and one of the reasons is that they are pretty quiet RF-wise. When you run wound core wires the noise level usually jumps because of it. That usually sounds like a tick sound in the radio that is in sync with the RPM.
The other source is the alternator. That is always there, but what happens there is the brushes wear over time and gets worse. There's not much you can to do stop it completely, but replacing the brushes can reduce it. This will sound like a whine, also RPM dependent.
The factory radio is usually pretty immune to this for a couple of reasons, but aftermarket stereos that have RCA interconnects are very susceptible to it. Be sure to keep space between any RCA signal wires and power cables and where they have to cross, do it at right angles rather than running them parallel. You can also shield the RCA cables and that can reduce some of the noise that they pick up. Avoid running RCA cables near the ECU or any sensors, near cell phones and other gadgets, other radios (like ham radios), etc. I would keep several inches (like 6", 8" or more) between power and signal cables.
The second thing is to be careful of your grounds. If you have poor grounds you can create ground loops because the positive side cable has a different impedance than the ground side, so you get an induced current and that makes a really good antenna. If you measure the power across the battery and the power across the power leads at the amp or radio and you measure more than about 0.25 or 0.50 volts different (i.e. the battery voltage with the car running is 14.4V and the power at the amp is 14.0V), you have a ground loop and that's probably a big source of your noise. If that's the case, increase the size of the grounds to as big as you can. Second, never tie more than one ground to a bolt. Ground the amp, radio and any other device to different ground bolts. Ground loops are the reason like 99% of the times you hear noise on AM.
