TJohnson

First off, I looked at all 4 pages of this section of the forum and found a few references to this issue, but not exactly what I was looking for.

I just installed my Alpine IVA-D900 DVD flip out screen into my 92 SC300. Everything went exactly accoridng to plan aside from those noises of course. I know all about the power and grounds being far away from RCA's, etc. But the RCA's and power/ground/12v switched are all on the same harness going into the factory wiring!

I have the autotoys harness that has the power, ground, 12v switched, remote turn on, and antenna and then has 4 RCA plugs, one for each speaker. Everything turns on, works great, and sounds great, aside from the noise. How can I isolate the wires from each other when they are less than an inch away going into the harness? I will eventually be going with aftermarket everything and this won't be an issue, but for now I wanted to run it this way just to have some sound and have a nice looking deck.

Any ideas?

bguild

You will need TWO ground loop isolators at Radio Shack, and two RCA female to female connectors. I had the same issue. Good luck.

suorum

Man this is SO OLD...and yeah it is true...that's ONE solution but the most SQ killing one. If you have only the stereo as an aftermarket part (powered one of course) just ground the stereo to the "chassis" of your car. Bare metal must be seen on the grounding spot!!!!!

bguild

Suorum,

I'm going to have to disagree with you on this... please hear me out, and offer your opinion..

I had no success following your grounding instruction at least on the 1993-1997 Pioneer setup on the GS300. I am using a Kenwood deck.

I did ground the deck to the big metal tube directly in back of the stereo. I drilled a small hole in it, sanded it lightly to get a good conductive surface, and grounded the deck to it using a ring terminal and a screw.

Still have massive alternator noise - unbearable in fact. The only thing that gets you by is the ground loop isolators.

So, are you saying I need to ground each speaker set to the chassis as well? If you are saying that, I will tell you no way in hell is it worth it. I will just plug and play on the ground loop isolators and loose a bit of SQ.

Your thoughts?

basketthis

Nope. Don't use ground loop isolators. Bypass the amp. Essentially, you will be running four sets of speaker wires to the amplifier and pick out the wires that go directly to the speakers themselves and hook them up accordingly. I'm sure you can find the wiring diagram or someone on here could help with the wire colors! No more problems. You definitely need to run a new ground for the aftermarket radio though. GL!



BTW, ground loop isolators are worthless. Period. No argument...

ivory98es3

iTrader: (1)

You don't have to "bypass" the stock amp.....you can keep it and have perfectly good sound with out any noise. I was able to do it in my ES300 w/ my Alpine W205. My solution was to pull power and ground straight from the battery. That metal tube/bar you have it grounded to right now is crap....Alpine's are very sensitive to current changes and will induce noise if not grounded out properly. Also, if you have done so already, upgrade the grounds from battery to chasis & battery to engine to 4awg or bigger.

If you "bypass" the stock you will lose the stock sub.

Hope this helps.....

basketthis

lol!! No offense, but I hope you didn't run a ground all the way to the battery!! That's probably the worst thing you could do...

But, yes, I find it easier to just bypass the amp, although I didn't say that it HAD to be done...

Whichever route you choose, GL!!

bguild

guys, the original post is hella old so I bet the guy figured it out, but I gotta know... so pls clarify. I prefer to not use the ground loop isolators, but I also need to use the stock amp right now. What then is my correct answer for grounding, not using ground loop isolators, and, most importantly, not having alternator whine?

According to your answers above, no to the metal bar, and no to grounding directly to the battery itself... so where?

My current situation:

1) ground from aftermarket deck to metal tube in back of stereo
2) each RCA channel (FR,FL,RR,RL) is grounded individually back to the RCA plugs. What I mean is, in the stock 15 pin harness, I've pinned those specific negative wires back to individual ground wires for each channel in the Metra harness. Let me show you a picture of my modified harness so you understand what I am talking about wrt to RCA grounds:



RED,BLUE,YELLOW AND BLACK ABOVE ARE THE GROUNDS. So what you are seeing above is that RF+,RF-,LF+,LF-,RR+,RR-,LR+,LR- all pin directly into this connector below (look familiar?)



By doing it this way, you sort of have a shot at reattaching the stock headunit in the future with little grief. On the other hand, if you take it to Best Buy or Circuit City, they will snip your stock connectors right off. not cool.

Finally, pls clarify, why is that big *** metal tube a crappy ground? The thing is absolutely huge, and it's attached to the chassis. In principle, it would seem like an ideal ground.

basketthis

The answer is: You need to make a new ground for your aftermarket radio to behind the driver's kickpanel or as close as possible. You also need to reground the factory amp to the closest bare metal as possible. I'm not sure of the location of the amp in your vehicle, but if you need to scratch some paint off behind a panel or under some carpet and drill a screw to hold the ground onto the bare metal. That should do it. You never want to run a ground wire all the way back to the battery. Ground should be as short as possible. And being that the all of the metal in the car is grounded, you need to find the shortest way possible to the closest "true" ground, which would actually be the frame or any metal that the negative battery terminal is connected to. Hope that helps.

BTW, Circuit City won't cut your harness. They use aftermarket ones just like the one you have. At least, around here they do. (can't speak for Best Buy, but I'm pretty sure any stereo shop would use them)

Big *** metal behind the radio will be fine for grounding your radio (usually). You want to have the best ground possible in this particular situation, so just run it to the driver's kick as I have explained. Do the same with the factory amp and that should solve your problems!!! GL!!

bguild

basketthis - your answer really helped me, thx - I appreciate it

basketthis

Great! Glad I could help!
I'm guessing it solved your problem?
I'm sure you already figured it out but you can put your harness back together the way it came. No need to ground and re-pin the harness....

bguild

havent tried it, but I follow you and will update the post when I complete this.