CB and Stereo Help

[76/85 Truck]

Hey guys

I have an amplifier hooked to my stereo.. and when I key the mike on my CB I can hear myself talk and hear feedback through my speakers...

Also, when I'm driving down the road I can hear a whining noise, varying with engine RPM.. HOWEVER, it also has a whining noise when key is on and engine OFF... and it seems to be in conjunction with the electric fuel pump noise.

What could be causing my CB to come through my stereo, and what could be the whining noise?

RCA cable is under the carpet up against the floorboard, but the RCA is insulated. The Antenna wire for the CB is running along the passenger side and up through the door, and is a magnet mount on top of the cab.

All grounds are good I believe... Stereo is grounded to a dash bolt, and CB is grounded to the CB Bracket. Amplifier grounded to seat bolt.

Thanks a BUNCH for reading!! Please feel free to voice your opinion.

[juiceman650]

For your grounds, make sure to ground to bare metal and that they are tight and not "wiggling around". The "whining noise" is because your RCAs have come in contact with another wire that is carrying a high amount of voltage (such as a power wire for your amplifier).
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[76/85 Truck]

Where would the feedback from the CB be coming from that is going through the speakers
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[juiceman650]

I'm not sure about the CB feed back. I have 0 experience with CB radios, but a lot with car stereos, amps, etc. Can you describe what exactly is happening with the CB and your speakers?
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[67_SS396]

The feedback is caused by poor grounds. Try a larger gauge wire, make sure you scuff the paint off and look for an area close to the frame.
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[76/85 Truck]

when I have the stereo off, I can press the mike and nothing will happen. When I have the stereo on, but on pause or aux with nothing plugged in or something along those lines, I can press the mike and hear a squealing feedback and I can hear myself talk into the mike. It's rather annoying between the buzzing engine rpm noise and the CB feedback...

Thanks!

[juiceman650]

Hmm, the only thing I can think of is bad ground also. Do you have the CB running off the same power supply as your stereo (such as connecting the CB power wire to the stereo power wire)?
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[76/85 Truck]

The CB is hooked to the fuse box so when i turn the key on it comes on, and the stereo is hooked to a different place on the fuse box... The Stereo is grounded to a bracket on the dash.. and the CB is grounded to the hole in the dash where the CB bracket bolts to.

[juiceman650]

Yeah, you DEFINITELY want to change those grounds. Try to get them on to a sturdy, paint free, rust free surface of the cab. Unless you can ground them straight to the frame.
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[76/85 Truck]

alright... would the RCA cable being right up against the floor make a difference? It is, of course, covered in rubber but still. And the wire that remotely turns on the amp when the stereo is turned on is running right next to the RCA, would that make a difference at all too?

Thank you so much... I will change grounds tomorrow

[juiceman650]

The remote wire is safe to run with the RCAs, I do this on every car audio install I've done and never had anyone complain, and yes its safe to run against the floor as long as their are no tears on the insulation of the the RCAs or remote because the can short/ground out. You DO have a mechanical fuel pump right? Because if you run your RCAs over an electrical pump, that can cause the RCAs to go bad as well.
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[76/85 Truck]

Nope... i have an eclectic fuel pump that comes on as soon as the key is turned on
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[juiceman650]

Ohhhh, okay. Well just double check to make sure your RCAs are not running down the same path as the power wire for your fuel pump.
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[76/85 Truck]

The buzz from the speakers with the engine off and key on have the same type of hum as the fuel pump... I'm thinking ground...
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[Prerunner1982]

Run the power and the ground for the CB directly to the battery. Separate the wires for the CB and the wires for the stereo as much as possible. I had a similar problem in my Jeep when I had my amp and speakers in it, the RCA cable was running along the transmission tunnel, right by the wires for the CB and by the CB itself. Unhooked the RCAs from the stereo and it took care of most of the noise. I think power and ground to the battery should fix half of the noise issue you have.

[INSIDIOUS '86]

if your antenna is close to your steareo antenna it can prob cause feed back. and dont just ground the antenna to the cab, ground EVERYTHING together cab, bed, hood doors etc... keep the rca away from high power/amp wires and ignitions systems

[Psycho71]

I had the same issues a few years back in a pick-up where I had amps on the stereo system and a linear on the CB. With the linear on, it would bleed into the stereo equipment extremely bad. With the stereo system off, it would not do it. I re-grounded everything a few times trying to stop it, even re-routed the rca's and coax a couple of times. but nothing would stop it. i could turn the linear off, and it wouldn't do it.

I'm thinking my issues were different than what you're experiencing because I was swinging about 400watts thru the linear. Plenty of power to explain the bleed over into the rca's,crossover, amps, etc.. It was frustrating though.

Another to look into on the whining sound you are getting thru the stereo....Plug wires. Bad plug wires will/can cause the whine you are getting. Also, lots of good info on the grounds here. But you also ned to make sure that your vehicle is ground-strapped properly too. Well connected ground straps should connect the battery to the engine, the engine to the frame, and the frame to the body. Any combination of the above will work. But they all need to be in place, and all well connected with star washers to clean metal surfaces.

[76/85 Truck]

Well, I regrounded EVERYTHING to clean metal. I wired the CB straight to the battery, hot wire to positive, ground wire to negative. I put the wires through the same grommet in the firewall as the 12v power wire going to the amp, is that bad?

I still have the whining noise... dont know where to start. (filter for the RCA possibly?)

When i key the mike for more than 3 seconds, the speakers start squealing again... (Bad antenna maybe? Bad Coax causing leaking signals?)

The only time I have the whining noise now is when i drive down the road with the stereo on either pause or on AUX with nothing plugged in... so basically when the stereo is on but on an "idle" type thing... or if the volume is very low

Any help is greatly appreciated.. next step I'm thinking an RCA in-line filter... and new Coax and CB Antenna (antenna is old)

Thanks!!

[67_SS396]

What kind of antenna are you running for the cb? Is it a magnet mount or a stick? If its a stick, look at the ground. I have a cb with a 102" whip and I have an amp and 12's hooked to the stereo. The only noise I had was when I turned to AM, so I put the amp on a switch and turn it off when I listen to AM. I still say you have a ground issue somewhere.
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[Prerunner1982]

I would agree there is still a ground/wiring issue somewhere. If it is not a mag mount have you checked the grounding at the antenna?

[Kurt L]

get you some condensers and put one on your hot wire for your cb radio,and get your cb off the fuse box. run you a number 10 wire for your cb radio to the battery,also put a condenser on your alternator. that will stop your whinning in your cb if you run everything off the fuse box you''ll hear your wipers, your blinkers etc. i had to do this with my cb radio and worked quite well.you'll never get rid of your fuel pump noise tho been there tried everthing i could think of,and never got rid of the pump noise.make sure your swrs are good also that helps out with your recieve and transmit,also you won't burn up your radio with high swrs.[stanard wave ratio].you can take the stinger of your antenna and move it up or down to set your swrs also gotta have a meter to do this with. if your swrs are higher on channel 40 then on channel one you need to make yor stinger shorter,if higher on one then on 40 you need to raise your stinger. if you have a fiberglass antenna theres a wire under the cap that you can cut if your antenna needs to be shorter.but if it needs to be made longer then you use a different length coax.make sure that the plastic groment is on top of your antenna brackett also.theres a little ring on the bottom of the groument that sits down in the hole of your bracket.make sure that you tighten up your stud kit so you don't loose your antena but don't crush the plastic groument.

[Dan1969]

^^^ The condensers are capacitors right? That's what has seemed to work for me on regular radio installs for higher frequency speakers (tweeters) when I can hear the engine noise and all the grounds are attached properly.