CB Noise.... Still

mrese · 11-03-2009, 04:07 PM

Still dealing with bad noise on my CB when the engine is running only, it is a high frequency noise varies somewhat with RPM.
Question I have on each side of the engine at the spark plugs is a device that bolts down with the Coil.
Could that be a noise suppesor??
I wil lget a picture tonight maybe.
Does some one have a Shop Manual that might explain what this is.

And yes I know you need pictures........

**EisBlade** · 11-03-2009, 04:19 PM

Make sure that your Neg. wire is grounded well to the body of your vehicle, not the sub frame of your dash or other components. Engine noise is usually the cause of a bad ground or running your Pos/Neg wires next to your amplifiers power wire...or sound/RCA lines if running a stereo system.

If the pitch of the noise varies with engine rpm's then it's alternator whine/engine noise. Basically, your car or CB isn't grounded well. Where does your 12v feed come from for power?

Try this: run a test line off both the POS & NEG terminals of your battery and connect them directly to your CB. Then run your tests for noise with that configuration. If that doesn't work then stop by any radio store (Best Buy, Radio Shack, etc) and pick up a line/noise suppressor for your 12v feed. Let us know what you find out.

CLNinja · 11-03-2009, 04:25 PM

run your POS and NEG wires directly to the battery ... not to the body or anything

leaf001 · 11-03-2009, 05:11 PM

Take a wire brush and clean off the terminals to ensure you have a good ground.

mrese · 11-04-2009, 12:01 AM

I am running power straight from the Battery, have checked most grounds I can find, New Alternator, Tried several different area's for ground, I have changed plugs,
Covered most the basic stuff. This is why I am looking in to other options.

CMARJEEP · 11-04-2009, 02:28 AM

I would check to make sure that all the ground straps are in place. There are a couple. One that goes from the engine block to the chassis and I think theres one that is by the transmission too. I have seen people that add straps too to their exhaust and other things that are isolated from the body and it seems to help a little. Also, make sure your power wires are being run away from any other wiring because that will tend to cause some noise.

Edit: and when do you hear the noise? Have you adjusted your squelch? Does your radio also have an RF gain control? If it does, turn it down to about 9 o'clock. Can other people hear the noise when you are transmitting to them?

mrese · 11-04-2009, 05:25 PM

Yes I can not transmit it is just Squeal, just kills the whole unit. I havent looked for one at the transmission, the one at the engine/chassie is good, I took it off and cleaned under it also. I have the wires run across up by the cowl away from what I can tell all sources. PUZZLED!!!!!!!!

CrazyIvan888 · 11-04-2009, 05:33 PM

Have you tried a different radio, just for kicks?

Manche87 · 11-04-2009, 05:35 PM

how do you have your antenna set up? i just had this same problem and it turned out my coax cable to my antenna was not grounded right...

Manche87 · 11-04-2009, 05:38 PM

This diagram helped me out a lot

manderson2228 · 11-04-2009, 05:39 PM

Quote:

Originally Posted by mrese

I am running power straight from the Battery, have checked most grounds I can find, New Alternator, Tried several different area's for ground, I have changed plugs,
Covered most the basic stuff. This is why I am looking in to other options.

Run your ground from the battery too... This is just about always a bad ground.

manderson2228 · 11-04-2009, 05:40 PM

Quote:

Originally Posted by mrese

Yes I can not transmit it is just Squeal, just kills the whole unit. I havent looked for one at the transmission, the one at the engine/chassie is good, I took it off and cleaned under it also. I have the wires run across up by the cowl away from what I can tell all sources. PUZZLED!!!!!!!!

Hrmm.. if it's just a squeal... It might be your ant is not tuned properly.. Or if the radio is used. the finals are blown..

CrazyIvan888 · 11-04-2009, 05:42 PM

^What he said. I assumed you were running both wires straight from the battery when I read your post, but yeah, if your ground is grounded to the vehicle it is most likely the cause of your problem.

CI888

**EisBlade** · 11-07-2009, 03:40 PM

I know someone mentioned conducting a test using direct connection to the battery terminals..ahem.

I'm reading 2 issues here rather than one if you have CB squeel too. This isn't hard; you just have to break this down and start from scratch. Since it's not working correctly inside the vehicle, then take the CB out and bring it up to the front of your Jeep. Hook it up using SHORT power leads to the battery terminals. It's the only way to eliminate everything. Once you do that, and we can confirm that you have no line noise there (and no CB squeel as well) - we can move further from the battery with your power leads.

(note: CB squeel is from either bad finals as mentioned already (the 'power pills' inside the CB) or a bad antenna cable)

IF SQUEEL IS PRESENT - change to a different antenna making sure it is properly grounded to the vehicle.

IF NO SQUEEL - turn the Jeep ON and listen for line noise. If no line noise at the battery than you have a bad connection inside. Rewire, connecting BOTH power leads directly to the battery. Also be sure not to run those power leads along other existing wires (sound, power, etc) if possible. They could pick up line noise from other wires.