City horn feedback

Sounds Ground related. I have a similar problem in my truck but its with my wiper washer. When I hold the button to squirt the fluid the cb makes all kinds of racket

 

For both problems, it's either RF being radiated by the horn or pump motors, or it's from pulses riding on the DC line that feeds the devices and your radio(s).
In both cases, see if the noise is diminished with the antenna unplugged from the radio. If not, then you'll be best served by filtering the DC to your radio. If the noise drops, then the devices are sending a noise signal over the air, so you need to stop the noise at the source, with bypass capacitors right at the horn or washer motor.
Question for MassHole: do you also hear the wipers, or just the washer pump?
-- Handlebar --

 

Thanks. No its only when the pump is going. Other then that its fine no noise at any other time

 

Motors that have brushes are kinda like anything else that causes sparks: they transmit RF energy through the air over a wide range of frequencies. Not necessarily very far, but enough to be heard by an antenna that's close-by, or picked up by a DC line working like an antenna.
The Titanic ocean liner used a spark gap transmitter, coupled to an antenna, and was heard for very long distances sending CQD CQD (the forerunner of SOS). So we know it works
Sounds like the pump motor is a brush type. A bypass capacitor from the positive pump terminal to the nearest ground you can get it to should solve that problem, although it'd also be interesting to see if you hear less of it with the antenna disconnected.
Another valid point you mentioned is the possibility that it's ground related. If anyone has a radio that won't power up until the outside shell of the coax is screwed on to the radio, then it means the place you've got your black power lead fastened to isn't really an electrical ground. When that happens, the only DC ground you have is the one at the far end of the coax, at the antenna mount, which will cause all kinds of noise and low voltage problems, especially when you're transmitting.
<whew>
I'll wait and see if any of these ideas help you two folks (or anyone else who's reading this thread
-- Handlebar --

 

I get a "pop" when I use my turn signal, and the other issues above (city horn/washers) I have a day cab with +/- hookups in the cavity for the CB & just learned to deal with it. This is a Co. vehicle and I don't want to put too much into it.