Galaxy DX 94HP

If I understand, you are saying that you have the positive power wire going from the radio to the battery, and the radios ground wire going to the trucks chassis? If this is so, you may be dealing with common mode problem, maybe due to an RF ground loop. You need to run the radios ground wire to the battery too. Don't forget to put fuses on both wires close to the battery terminals for safety.

 

Why do you need a fuse on the ground wire?

 

The first time someone mention putting a fuse in the negative wire to the battery, I had the same question as to why. I think it was on this forum on another thread a few months ago, that this question was brought up. The answer that was given sounded logical to me at the time. But after doing a quick research on that myself, since the older CB radios used to have a negative / positive ground switch on the back of the radios, I believe it was considered a floating ground. That was many years ago with the older vehicles and the way they were designed. But nowadays things are changed with all the electrical devices in the vehicles. So it appears that the worst thing you can do is put a fuse in the negative ground wire, plus you don't want to run the negative ground wire from the radio directly to the negative battery post. It looks like now they recommend that you run the ground from the radio to the chassis nearest the negative terminal of the battery. It has something to do with a higher currents with some more modern-day powerful radios that are being used, and they could cause what's known as an open ground Loop if the fuse was to open up on the negative ground wire. Which of course could be a bad thing not just your radio, but maybe some of the electrical devices in your vehicle. So I guess I'm going to have to remove the fuse on my negative power lead in my pickup, and move the ground wire to the chassis nearest the negative ground post. Thanks for asking that question, now I know that's not the correct way to hook up the ground wire in the vehicles today. I guess I learned something new, even though for many years , I've always hooked both the power and negative wires directly to the my vehicles battery.

 

Well after a little more web surfing, I came across this link by cb radio magazine.

Power wire hookup - battery or cigarette plug | CB Radio Magazine

They are suggesting running the power and ground wires to both battery terminals, as one method to power the radio. Now they don't exactly come out and say to fuse the ground wire, but they do mention putting fuses (plural) close to the battery terminals.

Unfortunately instead of helping the OP solve his problem, I maybe complicating things.