Boom... out of nowhere, I'm getting engine - radio feedback.

[Dadnatron]

I had a new 'radio' put in my F350 about 6mo ago, and its been working fine. I was driving on a slightly rough road yesterday when all of the sudden, I began getting severe radio feedback from the engine. Like the ground or whatever has fallen off or some wire is touching something it shouldn't be. It is in all speakers, as far as I can tell.

The truck is used, and the guy before me had an amp installed, which is required to run the speakers which are in it, according to the radio installer.

The noise is worse than anything I've heard before, but is directly related to the engine rpm. It occurs regardless of whether the sound is up/down and has no bearing. It is loud and stays that way.

I'm sure something is just 'loose' but I am not a big electronics guy, and the guy before me had a bunch of crap wired into this truck. To the point that the installers (I've used them before, they are custom guys) had a major ordeal just putting in a double DIN system. I just wanted to wirelessly hook to my iPhone.

The question is... given I have an AMP and this new radio... any recommendations on a likely culprit and where to begin looking?

 

[cdaigle430]

I had a new 'radio' put in my F350 about 6mo ago, and its been working fine. I was driving on a slightly rough road yesterday when all of the sudden, I began getting severe radio feedback from the engine. Like the ground or whatever has fallen off or some wire is touching something it shouldn't be. It is in all speakers, as far as I can tell.

The truck is used, and the guy before me had an amp installed, which is required to run the speakers which are in it, according to the radio installer.

The noise is worse than anything I've heard before, but is directly related to the engine rpm. It occurs regardless of whether the sound is up/down and has no bearing. It is loud and stays that way.

I'm sure something is just 'loose' but I am not a big electronics guy, and the guy before me had a bunch of crap wired into this truck. To the point that the installers (I've used them before, they are custom guys) had a major ordeal just putting in a double DIN system. I just wanted to wirelessly hook to my iPhone.

The question is... given I have an AMP and this new radio... any recommendations on a likely culprit and where to begin looking?

You may have to install and inline filter between the amp and the radio. Check all you cables and ground for sure.

 

[/pine]

The alternator is the first thing I would check but could be several things...

 

[Industrial Toys]

Ignition or alternator noise getting into the amplifier. If it was OK before than "clearly" something has changed and you don't need to start adding things that were not there before. duh!

I'm thinking some components in the power supply filter have failed, or maybe broken loose from the circuit board.

 

[Jstpssng]

If you plan on keeping the truck you might also consider yanking out or replacing any aftermarket wiring that your guys didn't install. Sometimes starting over is cheaper in the long run.

 

[reb]

I would check the ground connections in the areas of the radio and amplifier first. Shouldn't be an expensive fix.

 

[Argonne]

Along with what others have said, it could be a ground degraded somewhere. The coax leading from the antenna to the radio would be a prime suspect...check that any connectors are tight along with the antenna mounting to the body. Troubleshoot while listening to the noise whenever possible, if it goes away momentarily while you are manipulating something you get a big clue. Any large body segment becoming un-grounded can cause this. Main suspects will be up front starting with the hood and followed by the fenders. you should be able to check bonding with an ohmmeter, or just go poking around with a ground jumper and see if grounding any body panel makes a difference.

 

[Industrial Toys]

Poking around on a modern vehicle isn't that easy. An airbag may even go off in your face!

I would suspect the usual total lack of craftsmanship and knowledge in the aftermarket stuff.

A friend who does Mobile Inverter Installs on Utility Vehicles recently told me of an install he saw with BX cable going under the vehicle. Pathetic. Some guys think, if it works when it leaves the shop, they have done a good job.

 

[flyerdan]

First thing to test is does it affect a nearby radio as well, or only the onboard one. That will tell if you have an ignition shielding issue, or something else.
Back in the day before resistor spark plugs and wires were common, it wasn't unusual to hear an older rig coming up the driveway on the am radio.

 

[skipperbrown]

As mentioned above, it is likely a ground issue. Loosen, twist and tighten again all the grounds you can find especially to/from the alternator.