Alt noise.
 

ok my van runs 2 different alts one for the van one for the system. alt for van powers van only. i added a second chevy alt system has played fine. in the last couple days i tried hooking up a 2nd 4 channel amp rockford fosgate t-400.4. soo as i hooked that up the speakers hooked to it would wine and screached for a bit. i have my 2nd alt on a switch to turn it on or off does not run threw computer. so i un hooked my other 4 channel amp put the hook ups to the RF and it played fine. i rehooked the mb quart 4 channel ran fine tried to hook the RF threw the out put from mb quart still noise. nothing else make noise but the new amp and speakers just installed. i get whine even when car is off if the alt switch is on i shut the switch to alt off the whine buzz stops. i unhooked my censor charge wire and all noise stopped so some how its coming from the alt sence wire. alll grounds good to bare metal no power close to speaker wire or rca's. i also tried another head unit on the rockford and it worked fine . oh forgot i dohave the mb quart running off the vans alt..the system is run off of its own alt to batterys in the back to my bass amps. it has me stummped ive been at it for 3 days trying to eliminate the problem.. any idea why the sence wire would create feed. i know it has something to do with that cause soon as i unhook the =sence wire from batterys the noise stops. any clues why everything else plays fine but when the RF is hookked it buzzes humms even when not running. it seems when i start it i dont here the noise but i may be misleading myself because the music drowns it out.. any suggestions are greatly appreciated. thank you.

On the amp that is causing the noise take your ground off of where it is at and go directly to the battery.I know you said it has to do with your sense wire, but just do this test as you have a bleeding problem and usually when this happens this has to do with a bad grounding point. Another thing to do is to add another ground to your battery with 0 guage wire and ground it short as possible to your motor block.

Thanks i will give that a try tomorrow i have not done the big 3 because as i said i
 

i will try that tomorrow i have not done the big 3 because as i said i have seperate alt for audio so i will give that a try tomorrow .. thanks appreciated.:thumbsup:

Sorry if I ask any questions that you answered, i had a hard time understanding you...it sounds like since the MB quart amp is running off the vans alternator, the RF amp is all thats running off the extra alternator? do you have system ( lots of subs i assume) running off that extra alternator?

what is that extra alternator rated at? whats the draw from that alternator? why is the MB quart amp hooked up to the vans alternator and the rest not?

Sorry if i confused you.. the mb quart has always ran off van alt the RF was being added to that system, yes the other alt supplys power to my 4-HCCAs and 2 soundstream x3.71's, the hi out put is a 220 amp. I ran the smaller power amps off the van so theirs no strain on vans alt i added the HO to power the class Ds. the HO alt only powers the sub amps, battery's. Its a Mercury villager [nissan built] the HO alt added was a chevy small case. everything is fine untill i hook up the rockford. thought amp was bad but hooked to another head unit and speakers ran off the class D amps power and worked fine. ran it off van with out MB Quart hooked up and ran fine also. i started some better engine grounding today but didnt get it finished to test it.got dark on me..lol Thanks. PS it all works fine untill i try and add the RF. its a T400.4 POWER SERIES.

whines are tough to troubleshoot. Thanks for the clarrification. so have you tried running all of the wires to the outside of the van and try hooking up outside? it might be easier to troubleshoot. you can try different RCAs, better ground, so on.

will try
 

thanks im going to try that tomorrow even though all power is on one side speakers rcas on other .but i will try it never hurts. I have never had this problem in 30 years.. im sure its something stupid im over looking some wheres..