Hey guys,

About a month ago I put in my CB (cheap one from walmart), and two 4' whips on the front of the bed. My CB works great when the truck isnt running, but when the truck is running all i get is static from the engine. Is this because my cable is ran through the firewall down under the truck, or is this just another issue?

Thanks for the help.

 

Depends on what kind of static you are getting.... If it is just white noise.... might want to look at the power feeds. If you are hearing ignition noise, re-route your cables.

 

i think u figured it out urself already, i think its gettin some static from the other wires. how think gauge is the wire? might try re-routin it, or a bigger gauge wire.

 

Well I think the best way to describe it is that the noise is a static, but when you rev the engine, the noise goes right up, like its the engine giving interference. The only cable its run next to that i know of is my Amps power wire.

 

Ignition noise. What kind of spark plug wires are you running?

May want to avoid the power cable for the amp as well......

 

Well ive left the power cable alone because theres no interference with it. I think im just using duralast or whatever autozone sells for spark wires.

 

I haven't spent much time analyzing the noises from my Dodge yet but one of the biggest offenders on my old Ford F150 is the fuel pump circuit. There is actually quite a bit of power being drawn by the fuel pump through its fairly long leads. A little RC filter at the pump seemed to work wonders for me on the F150. You might try listening for increases in noise when you hear the fule pump relay clicking.

I love listening to cars with my radio. You can always tell the best electrical designs by how quiet they are. Hondas are absolutely silent while Fords are a rolling RF nightmare.

Of course as others have pointed out prper layout is critical. Any problems caused by the vehicle itself will be made more evident by improper layout/cheap or kinked cables etc.

 

One man's quest for reducing RF interference.

Something to note though, his 'cheap' radio was a part of the problem.

 

If the pitch of the noise changes when you rev the engine - then you possibly have a grounding issue. Make sure the antenna mounts are grounded well - if there is paint or something between them and pure metal you may need to run a ground wire from the mounts to the frame. My K-40 antenna is mounted on the tool box, so I ran a large wire (like 10 gauge) down to the frame. Also check the ground wire on the radio itself and make sure it is to a good ground.

 

I put grounds off my two custom mounts, which I mounted to the bed with home made brackets, didnt do the trick. And my power and ground to the cb itself is good because it is the same power and ground for the radio.