Hello,
I have a 2018 F250 CCSB, 6.2, XLT+, 35k miles. I have an old Uniden 510XL CB that I recently installed with the fender mount antenna recommended in the other threads in this forum. I initially tried the CB using the cigarette lighter outlets on the dash and center console. Radio powered up and could receive fine. When I pressed transmit, the truck would start chiming, engine would rev up and it would throw fault codes for the hill descent control and traction control.

i sent a message to Right Channel Radios and they suggested wring the CB power directly to the battery and the negative to a good ground. I did that yesterday, the the radio still receives fine, but when I press transmit the engine revs up.

has anyone else had similar problems? The CB radio is at least 20 years old, but has worked fine in other trucks. My next step was to try a new one. But I am open to any other suggestions.

Thanks
Kevin

 

It might not have anything to do with the power supply, but RFI with the ECU or BCM or one of the other alphabet modules. Something isn't shielded well enough. Is your rig legal in terms of output? I won't tell, promise.

 

I would check for signal riding on you CB radio power supply from the battery. You could probably isolate the question of RF mentioned above by powering the unit with a battery not connected to your truck. If it doesn't do it then, you'd be looking for that signal on the power supply. It would take an oscilloscope to see it to know for sure that's what's going on.

 

Hello INTP,

9 out of 10 times I track this sort of interference back to high SWR causing the antenna feed line to radiate energy. I do agree with the advice to get power from the battery and to use as short of a ground lead as possible. In our highly computer controlled trucks, it''s hard to say where the cigarette socket power really comes from. I would imagine some module provides the power so it can be turned off after time, etc... Pulling any decent amount of power from those sensitive electronics is probably asking for issues. Saying that... I would assume the relatively low 4 Watt power draw of a stock radio is probably OK from the cigarette plug.

Here are the things I check when i have an issue like yours:

Do you have a SWR meter? if so, I would hook it up and see where you are at. If you'r over 2:1 at any point in the CB range you could have an issue.

Did you cut the antenna feed cable when installing it? 17' long is a rather good length that will create a good impedance match at CB frequencies. If you cut the excess length when installing it, you could create a poor match and lead to poor SWR.

Did you coil up any excess antenna cable? Coiling up the feed line is a big no-no and will not only reduce performance, but could also cause unwanted interference.

You mentioned the radio is a rather old. Is the antenna old as well. Sometimes I see old antennas leak water into their structure which creates all sorts of poor performance and problems. If you have a second or spare antenna I would test with it as well.

Even if the installation is "ideal" it could be as simple as routing the antenna or cable too close to a sensitive module. If everything above checks out, I would suggest rerouting the antenna cable intentionally away from under the dash and away the engine.

I have never tried the fender mount, so I can't comment on any specific challenges with that method.. I suppose others have made it work so it should be ok.

I hope you get it figured out.

Take care

KG4SRY

 

I do have the excess antenna cable in a coil, right next to the throttle potentiometer and my throttle commander.

What is the best way to deal with excess antenna cable?

i will report back my results.

Thanks
Kevin