My 1979 F350 has engine noise on the radio.
I have noise filters on the power feed & the antenna.
I have a Pioneer radio & Sertex amp.
The radio is wired to the factory radio plug.
The amp power is at the battery.
any suggestions.


1979 F350,4x4,NP435,5:13 gears,Detroit locker in rear with hardened shafts,ABR in the front,360 with 428 crank & rods,390 HP heads,Centerforce Dual Friction Clutch,MSD Ignition,39.5x18 Boggers,bucket seats out of a Lightning,& a Southern Body that is perfect.




1997 F350 PowerStroke 4X4,36 Inch Super Swampers, Strait Piped, Chiped, Propane Injected, LUK Clutch

 

Not really sure how you have your system setup, but if the engine noise is coming from the speakers that are powered from your amplifier you may want to try a "Ground Loop Isolator" you can buy them at Wal-mart for a bout 10 bucks. Various shapes and sizes, but most are albout 4-5 inches long with RCA connectors coming out of both ends. Just unplug the RCA wires going to your amp, plug them into the isolator, then plug the isolator into you amp, easy money.

Good Luck

Murph

 

Is the ground wire for your amp the same size as the power wire? Did you scrape all of the paint off of where you grounded the amp? Is your power wire to the amp within 12" of your RCA cable? If your ground wire is too small or not grounded well enough to the body, that can cause noise, but the #1 cause of engine noise is your RCA wire too close to a strong power source i.e. your amp power wire.
hope that helps.
Josh00

 

u need a new filter

 

try to figure out if it's altenator or ignition noise. If you rev the engine and turn the key to acc, the ignition will quit, but the altenator will keep charging as the engine coasts down. If the noise quits with the ignition, you need to take care of that with resistor plugs or wires. Most altenator filters won't help ignition noise. It's a place to start. Mike, KG7VL

 

It could be your alternator going down hill. My stereo hummed and buzzed for 2 months, getting worse as time went on. Until the alternator went out. After replacing the alternator with a new unit the buzzing was gone. You might also want to try replacing your alternator with a higher output model because drops in voltage also cause buzzing.

 

OK, if the hum wasn't there before the addition of the amp, I would have to focus on the amp. Where is the ground wire for the amp attached?

Generally,a ground loop condition exists when an electrical system is connected through more than one way to the electrical ground. Currents flow through these multiple paths and develop voltages which can cause damage or noise. To prevent ground loops, all signal grounds need to go to one common point and when two grounding points cannot be avoided, one side must isolate the signal and grounds from the other.

That being said, I would just like to add that those so called "ground-loop isolators" are simply very large capacitors or a transformer that stops DC current from traveling the wire. Anything that alternates, like music or noise, will pass. They are really good for protecting your speakers from damage from high volt DC, wherever that may come from. They will stop a ground loop if one were to exist between the head unit and the amp, but since most if not all manufactures install capacitors on the in/outputs of their amps, I doubt this would be needed. Likely, the noise is being introduced in the amps' power supply.

One way to tell is by turning up the volume, does the noise increase too? If so, that means the noise is coming from the head unit and being passed to the amp. If not, you can't say much for sure, but you might assume its coming in at the amp. Just run all your grounds together at one point to eliminate this well-know problem.

Other causes for this type of noise are a loose speaker wire, non-resistor spark plugs, and maybe a crappy alternator from running it on dead batteries for months.