Can't get rid of interference noise

[USMstang]

I had a 79 F-150 that did the same thing. I did everything to try to get rid of it. I changed wires, checked harnesses, added a ground loop isolator,scraped paint off at the ground point. I also used a distribution block to ground 2 or 3 items and then one main ground from that point.
What fixed it???
Your ground wire (on whatever unit or component) must be at least the same size as the power wire. Its not a bad idea to use the next size bigger. You also should not have any breaks in your wire and the termination point needs to have an excellent contact point. Meaning you don't need barrel splices and crimps in the equation.
This should solve your problem. It did mine and I've always done it since with NO Problems! Keep in mind that you don't want to use ground loop isolators and other crap of that nature.

 

[keybrdcowboy1]

Well, here's an update. Today I tore it back apart, and I unplugged the antenna to see if that was it. No change. Then I ran a new ground wire from the head unit back to the ground distribution block, and sure enough, that got rid of most of the noise. There is still some there, but it is very low now. I would like to get it completely gone, but my friend is content with the way it is now. There arn't any breaks or anything at all in my ground wires, and they arn't quite as large as my power wires, but they arn't real small either. Something wierd (or so I thought); I reran the remote turn on wire from the deck to the back (just because I didn't like the way it was done the first time) and my amps were on even though the head unit was not on, nor was it even connected to a ground. (That sounds confusing the way it was written; the remote wire was still connected, but I had already disconnected the ground to the head unit) Is that supposed to happen? Soon as I regrounded the head unit, they turned off like they are supposed to. Also, you can hear the cd player through the speakers. Meaning you can hear noise when it first turns on and is scanning the cd, and when you switch tracks. Any of that mean anything to anyone? Oh yeah, one more thing. When I was playing around with stuff today, I was touching the fuse that goes to the amp powering the subs, and you could hear me touching the fuse though the subs. They were making scratchy type noises anytime I touched them. Is that normal? And when I took the fuse out for the amp powering the door speakers, when I put it back in, it made a real loud popping noise through the subs. Just throwing out as much detail as I can. Thanks for all the help so far.

 

[USMstang]

Like I said, the ground wires should be AS BIG OR BIGGER than the power wires for each component! You will have noise otherwise. It also sounds like you have the remote power wire connected to a 12V+ power source other than the deck. If the remote is wired correctly (meaning to the deck) it is not possible for the amps to be on when the deck is off. It is also a sure indicator that if you hook up the remote wire to a 12V+ constant source you will have serious alternator noise.
Sounds like you boys might want to go to Radio Shack and get a book on installing stereo systems, it will save you lots of time, money, and heartache in the long run. Good Luck.

 

[keybrdcowboy1]

Like I said, the ground wires should be AS BIG OR BIGGER than the power wires for each component! You will have noise otherwise. It also sounds like you have the remote power wire connected to a 12V+ power source other than the deck. If the remote is wired correctly (meaning to the deck) it is not possible for the amps to be on when the deck is off. It is also a sure indicator that if you hook up the remote wire to a 12V+ constant source you will have serious alternator noise.
Sounds like you boys might want to go to Radio Shack and get a book on installing stereo systems, it will save you lots of time, money, and heartache in the long run. Good Luck.

Believe me, I did not hook up the remote wire to a 12 volt power source. This is not my first install, just the first one I've ever had major issues with. And the noise happened even after I reran the remote turn on wire, so I am doubly sure that the wire was not attached to a 12 volt source. But I did think it was strange also.....

 

[USMstang]

The reason I brought that up (the remote thing) was in our drunken stupor, me and a buddy once did that. It was afterwords that we realized we had done more than just had a few beers during the install.
That is weird. Sounds like he's got a bum head unit. I'm puzzled.

 

[explicit]

I would take the grounds to seperate bolts on your amps, dont run them to a block then a bolt, what is most likely happeneing is your grounding your amps off of each other and the electric is takign the path of less resistance, witch would be the wires not the block, basically groudn your amps sepereate without a block on seperate sides of the truck on the chassis, thsi should solve your problem