Trailer brake electrical interference

[Bob E.]

We are getting electrical feedback in our truck radio everytime we hit the brake when we are towing our 5th wheel. We had the trailer on our old truck with no problen so feel the difference is in the new truck connections. Any suggestions?

[FirstDiesel]

What controller are you using?? Check all the connections, especially the ground connections. Make sure the trailer has a good ground point.

[FisHn2DMax]

Bob E,

I've had the same experience with trailer controllers causing RFI on my radio, especially on AM. Is the controller you have now the same one you had before, and if so, did you tow with it before?

When an electronic controller is hooked up to trailer brakes, it uses pulse width modulation to the apply electric brakes in proportion to the tow vehicle deceleration and forward inertia. The duration of the pulse determines how much braking will be done.

The long and short of it is, almost all electronic controllers that use PWM will generate RFI! Some controllers and vehicle stereo systems are better than others in the suppression of RFI and sometimes it depends on if you're tuned to AM or FM.

In my last truck, the brake controller would just clobber the AM band. AM band is most suspectible to RFI from an electronic PWM break controller. Also, the 03's with the upgraded Bose stereo system have a power AMP that drives it's 6 speakers and is also used for DVD cabin audio with the factory rear DVD system. This AMP seems to be on all the time when the key is in? I suspect my 03's Bose power amp is where the RFI is getting in? I noticed it is very sensitive to other radio equipment ( Ham radio, and Cell) so I'm not at all surprized you can hear your electronic break controller coming through your speakers. I have a Prodigy controller in my 03 and it's very noticable on AM and lightly audible on CD or DVD? Ironically my FM reception on the Bose system is so bad,the only thing it seems to pick up is the brake controller..LOL!

In order to not have RFI from the Brake controller, you could buy a RFI suppresion kit ( Choke and capacitor)and add it in series with the 12volt wire that powers the stereo. I've used/made RFI filters so I could operate Ham radios in my past trucks and not interfere with the stereo. It works well. While I haven't used Radio shacks, I know they have a low cost simple (low pass) RFI filter that you could easily install if the controller RFI noise is really bad.

Good Luck!

:D

[ 11-21-2002: Message edited by: FisHn2DMax ]</p>

[Bob E.]

Hi FisHn2DMAX, This sounds like the problem. We had a Tekonsha controller on our other(dodge ram cummins) truck. When we traded it in we left the controller and bought a new Tekonsha. When the shop installed the new one he balanced it far more aggresive and sensitive than the old one.I will go to Radio Shack and check out filters. Thanks!!! PS we don't have the Bose and it is on AM.