Hi gents,

I am having a steady buzzing in the radio (am only). It stops buzzing at between 950-1000 rpm. It buzzes everywhere else thru the RPM range.

I am thinking that it is probably the alternator, but I am looking for other ideas. I recently had the tachometer flaking out and cleaned the electrical connections. That appeared to cure the tach problem. Truck is running beautifully otherwise.

Thanks,

- Shawn

Shawn,

The alternator could be causing the problem. You can use a digital multimeter set on AC to see if there is any ripple on top of the DC the alternator puts out. Check out all the grounds in the engine bay to make sure they are clean and tight. Also, you may want to put a ground strap between the firewall and one of the hinge bolts on your hood to RF ground it since the hood is very good at transmitting noise.

Being an amateur radio operator, I have fought alternator and engine noise as long as I have had radios in my vehicles. My 6.5 is the first truly quiet rig I have ever seen.

Does the noise change it's tone as you speed up the engine? Like does it go to a higher pitch the faster it runs?

No change in "noise" with engine speed. Just steady except for the quiet spot at 950 RPM. Going to clean connections tomorrow and maybe run with the alt unplugged just to see if the noise stops. Also going to throw the grounding strap on the hood as suggested above.

It's a possiblity that the alt may still make noise, if that's the source, even if it's disconnected. You may have to take off the serpentine belt and eliminate it altogether.
Just a thought. Extra grounds is a good thing.

do you have your phone charging in your truck? happened to me. damndest thing. drove me nuts for like two weeks. noticed it when i plugged my second phone in and the noise got twice as loud. solution for me was tunes more important than phones. i just make sure phones are charging when i'm not in the truck.

I am having a steady buzzing in the radio (am only).
I guess you can only listen to the radio in the afternoon then:lol:

Just had to say that.

Weak grounds can cause that, but if it only does it on AM, then you might try one of those antenna amplifier/filter boxes that hook up behind the stereo, supposed to make your reception clearer and be able to pick up radio stations further away.

My makes that kind of noise but only on AM station and when I step on the brakes(really bad under a overpass)? I just change to FM before I step on the brakes LOL. I don't know what it is but good luck with it.