Marc, RFI as you know is in the air because all the wires in the car act like antennas and can even pick up noise from a car next to you. Grounds are good but a lot of it has to do with the equipment. Newer and higher quality radios have better filters and noise reduction built into them so going under a bridge you would get less interference. Some shops sell may sell capacitors that hook up to the hot wire going into the radio that will filter some of the noise to ground but a higher quality radio with a good antenna will now days filter it's self. I finally took out the Craig and put in a Kenwood and 99% of the noise went away. John Hervey www.specialTauto.com -----Original Message----- From: dmcnews@xxxxxxxxxxxxxxx [mailto:dmcnews@xxxxxxxxxxxxxxx] On Behalf Of Marc Levy Sent: Wednesday, July 04, 2012 2:36 PM To: dmcnews@xxxxxxxxxxxxxxx Subject: Re: [DML] Radio Interference Yes, I was speaking of the ground path at the radio. If the radio does not have a good/solid ground it is a common cause of all sorts of noises. --- On Wed, 7/4/12, birdwell77095 <birdwells@xxxxxxx> wrote: From: birdwell77095 <birdwells@xxxxxxx> Subject: Re: [DML] Radio Interference To: dmcnews@xxxxxxxxxxxxxxx Date: Wednesday, July 4, 2012, 12:53 PM The alternator has a new ground so I doubt it is that. Though the ground on the radio might be bad as you suggest. --- In dmcnews@xxxxxxxxxxxxxxx, Marc Levy <malevy_nj@...> wrote: > > If we are to believe some of the reports, you need to add a ground bus!! But, if we want to fix the problem for real.... > > Is the noise you are hearing ignition noise? or alternator noise? Are you running just the head unit (low power), or do you have external amplifiers? > > If it is ignition noise, the capacitor at the coil may be bad. You may also have a bad ignition wire or 2. One of the reasons "resistor plugs" are common in cars is to reduce the ignition noise. > > If it is alternator noise, then you probably have a ground loop. One common problem is if the actual ground wire to the radio is loose, dirty, or not connected at all. The radio will still work if it is finding a path to ground through some other device (like, the antenna)... But because of the added resistance in the ground path, you will pick up all sorts of electrical noise (like, the alternator whine). > ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links [Non-text portions of this message have been removed] ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2193 / Virus Database: 2437/5110 - Release Date: 07/04/12 ------------------------------------ To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: dmcnews-digest@xxxxxxxxxxxxxxx dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/