CB Noise?

[GreenF350]

Well, I had a hard time deciding where to put this, finally decided this was probably the best place. I have a Galaxy 959 in my truck that works GREAT when the key is off, but turn the key on and it gets quite a bit of static. I can still talk on it, but it cuts the RX range down quite a bit. I read about a lot of Fords having problems with noise from the fuel pumps, but I let it sit with the key on, engine off for about 3 minutes the other day and the static never went away. So, my question is...what is the cause of this static...Could it be the ECM? I know it is a power issue since it still gets the static with the antenna disconnected. I was previously convinced it was the vacuum pump and was just deciding how to go about messing with it, but I just read in another thread that the vacuum pump doesn't run constantly. What do ya'll think?
-Aaron

[GreenF350]

Oh yeah, It doesn't do it when you turn the key to acc, just in the on position and it doesn't get any louder or quieter with the truck running.

[jesilvas]

First if you had the radio on with no load (antennas or dummy load), BAD idea. You can fry the internals.
Does the noise go up as the RPMs go up?
Where is your power source tapped into?

[GreenF350]

It is only bad to transmit without the correct load...that will fry internals. However, no, the noise doesn't go up with RPM's AND it does it with the engine off as long as the key is on.

I am a bit ashamed to admit it, but right now it is into my cigarette lighter....with plans to be attached directly to the battery when I get the time to get it done. I know it is better that way, but do you really think it will make that big of a difference?
-Aaron

[jesilvas]

I thought it was bad to transmit with no load, as well as without the correct one.
So obviously it's not the alternator. Might be the fuel pump. Vacuum pump doesn't run enough unless there's a leak.
Mine is tapped into my fuse box on the radio fuse. Just made a hook with the wire and slid the fuse in with the wire hooked on. The last radio I had didn't whine but my new one does and I don't know why. I figured that radio power would be filtered so I'm not sure what's wrong.

[GreenF350]

Yeah, I know it is "supposed" to be connected straight to the battery. My wife told me it might help doing it that way. (She does radio maintenance in the AF) I figured you guys would be better equipped to tell the where the noise was coming from. (What component might be running, etc.) I have verified that it isn't the fuel pump, and apparently it isn't the vacuum pump (although maybe just to be sure i should diconnect it and try it out or verify that it does indeed stop running.) So what is left? Just plain old dirty power?

Also, just to clarify....it is bad to transmit without the correct load OR no load....but as long as you don't key the radio, no harm will be done. (Also, FWIW, my wife said it is worse to key a radio with an antenna connected but with a real bad SWR than to key one without an antenna connected....Doesn't matter though, I wouldn't recommend OR do either....lol)

-Aaron

[jesilvas]

Oh didn't know it was supposed to be connected there.
I think it is the fuel pump. How do you know it isn't?

That's the part I always forget. Bad to KEY it.

[Hardline]

What if you hoked it up. Turned on the key so that you get the noise, then start eliminating systems by pulling fuses one by one. This will tell you what curcuit the noise is coming from if you find that it clears up with a particular fuse out. JJ

[GreenF350]

Originally Posted by Hardline

What if you hoked it up. Turned on the key so that you get the noise, then start eliminating systems by pulling fuses one by one. This will tell you what curcuit the noise is coming from if you find that it clears up with a particular fuse out. JJ

That is a pretty good idea...I will probably do that later today or tomorrow. (I am getting ready to go out of town this evening.) SHOULD work good, after that it would be down to figuring out specifically what component on that circuit. Sometimes you can't see the trees for the forest.

Originally Posted by jesilvas

Oh didn't know it was supposed to be connected there.
I think it is the fuel pump. How do you know it isn't?

Yeah, I know that is where the CB/Ham guys always say to get power from.

As far as the fuel pump, if I just key on, but don't start the truck, my fuel pump turns off after a few seconds. You can hear the fuel pump if you climb underneath or stand next to the truck. Even when the fuel pump shuts off there is no change in the static.
-Aaron

[jesilvas]

Originally Posted by GreenF350

As far as the fuel pump, if I just key on, but don't start the truck, my fuel pump turns off after a few seconds. You can hear the fuel pump if you climb underneath or stand next to the truck. Even when the fuel pump shuts off there is no change in the static.
-Aaron

I thought the fuel pump stayed running and the fuel was just returned to the tank.