Installation tips to help avoid engine whine – Rockford Fosgate

What causes engine noise through a stereo system? How can I fix noise problems like whining?

Most engine noise is related to one of three things: power/ground cabling, high resistive (loose) connections, RCA cabling and placement, and vehicle charging problems.

B+ Power Cable

You should be using the correct-sized power wire for the current demands of the equipment you're using. We recommend at least 8-gauge power cable for each amplifier you use, although we'll recommend 4-gauge if you have 2 or more amplifiers due to the dynamic power requirements. Plus, with 4-gauge, you'll have the opportunity to add more amps later without having to re-run power cable. NOTE: The B+ cable MUST be fused 18" or less from the vehicle's battery. Your positive power cable should be attached directly to the vehicle's battery using a high-quality battery post adapter. Install the fuseholder under the hood using water tight connections.

Ground Cable

At the battery, all ground cables should be less than 18" long and the same exact size as the power cable. Another option is using a special braided cable (called bonding braid) to connect the battery (-) to the vehicle chassis. Upgrading the battery-to-chassis cable will lower the ground path resistance and provide a better grounding plane. At the amplifier & signal processor location, use the same method above by keeping each ground 18" or less. When utilizing several amplifiers and/or signal processors, it is very important to use a single grounding point to the chassis. It's best to use a distribution block for this. All ground connections should be bolted directly to a solid, thick steel part of the chassis scraped clean of any paint and secured with a non-anodized screw and star washer. DO NOT use the seat bolt as a ground for your amplifiers!

Source Unit Ground

Due to higher current requirements amplifiers place on audio systems, it's recommended to ground the source unit at the same location as your amplifiers and other audio equipment. This may sound strange not to connect the source unit to the factory wiring, but troubleshooting techniques prove it's always best to ground the source unit in this method to eliminate any possible ground loops.

RCA Cables

Your RCA's need to be run separately and away from any power cabling - like the power cable for the amplifier or any factory wiring harnesses. You shouldn't be running your remote turn-on wire with the RCA's; you should run your remote turn-on with an additional ground wire, so that you can ground your source unit to the exact same place your amplifier is grounded, and all power cables should be run down the opposite side of the vehicle from your RCA's. Your RCA's should be a high-quality type like our Connecting Punch or twisted-pair cables, and you need to make sure they're not pinched or there's not a screw run through them accidentally.

Vehicle Charging System

The car's alternator or battery may also have a problem. If you've loaded down the alternator for too long, it might be starting to fail, and will cause unwanted noise through the audio system. Additionally, a failing battery can pass noise through to your system too, but this is less common. To be absolutely sure, we suggest taking your vehicle to the dealer or an auto parts store that can load-test your battery and alternator - they can determine if you're having major problems. If you're simply not getting enough power to your system anyway, it would be a good idea to upgrade your alternator to a higher-output model for best performance.

High Resistive Connections For all your connections, regardless of power or signal, be sure your screws are tight, your crimps or solder joints are solid, and your cables are not frayed. Failure to do so will create high resistance in the "connection" which is an invitation for noise. For example, a vehicle with the proper wiring methods will still generate "engine whine" due to something as simple as a loose battery ground.

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