Car Audio Discovery

I've been dealing with alternator whine for a while. Today i found out that if you take a piece of speaker wire and ground your head-unit CHASIS to ANY of your rca plugs, alt. whine dissappears completely. I've read alot of post on this subject through-out the web and never read this as a solution. I've try'd everything everyone has ever suggested and it never worked. When i found out this solved the problem, i was amazed. If you still have alt. whine try this it might work for you too.

I grounded the outer ring of the rca plug, but that made it worse! I accidently grounded the rca to my HU CHASIS, NOT HU GND and alt. whine went away. I read all the stuff YOU suggested and it did'nt work. ALL i'm saying is this worked! DUDE!

dirty651.... the "solution" you came up with should be looked at from a diagnostic point of view only..... by grounding the shield of the RCA cable and the noise going away, you simply confirmed that you likely have an open ground in the audio pre-out section of the head unit.... a proper fix would be to take the HU apart and repair the open ground foils, not leave the wire connected to the RCA's....the pre-out section audio ground paths are usually filtered and buffered with SM isolation caps which you have now bypassed....

kudos on being able to track down the problem yourself!!    but keep in mind the reason you dont see this given as a fix to try is that it isnt really a fix... it's a backyard barney DIY fix.... i think most advice you would get about this is to diagnose where the problem lies (which you have done) and then from there have the actual problem corrected.....

Happen to know if Jeep Cherokee's have the same affliction??  I've tried a few things and haven't come up with a solution as of yet.  All external grounds are good and wiring runs are seperated.