ScrapMaker

This is pissing me off, I am in the process of installing a new amp, but before I do that, I am wiring up all my speakers for my 4 channel amplifier.

I've been using this same exact amplifier for years, with no problem whatsoever.

Today I ran a new power wire, 1AWG, and I put a 1AWG chassis ground from the top terminals of my optima yellowtop.

This loud hum happens when my engine is off as well, and it is also affected by window motors and door locks.

I've tried 4 different pairs of RCAs with no luck...

Also from everything I've heard in these forums, I decided to run a REAL ground for my headunt... so I cut the ground out of the harness and ran it to the chassis, (about 6" long ground wire) -- this actually made it MUCH louder and I can hear the deck 'working'... like I can hear noise in the speaker when the deck is accessing files, going from track-to-track etc...

the volume of the deck doesn't matter, I can easily overcome the loud noise by cranking up the volume.

it seems that as long as the amp is on, and the RCA is connected to the headunit, it gets wild squealing...


what is my next course of action?
I also redid the amplifier ground and scraped all the paint off... this is on the rear wall of the car...

ScrapMaker

btw its only a high-pitched sound... a sub won't play it.

NEEDAZ

Is this your DEH-P8600mp?

9177

You say you ran a wire from your - post on the battery? do you have a batt in the back? Try grounding the 1 awg from you chassis. Ground loop noise doesn't necc mean that you have a "bad" ground but that one of the grounds in your system isn't as good as another.

edit Reread your post. try another place to ground the amp to. Sometimes it takes a few trys. Also check you engine to body.

vrtc350

iTrader: (1)

Are you running your rca's next to the power wire? I have seen where running the next to each other will cause a noise similar to what you describe. If so try seperating them.

ScrapMaker

Okay I think I have determined I have a bad wiring harness, etiher the pionner harness, or the GM interface harness...

Forget for a minute here that I even mentioned a BX1605D, because this problem has nothing to do with it, and yes I'm using the DEH8600MP from Pioneer.

Problems I am having:
- Loud sqealing/rumbling with Ignition completely off (sounds like I can hear the internals of the CD player through the speakers... like drive access noise, overall noise, not like RCA interference) -- pull RCA's off amp and sounds go away
- RPM specific interference --- must be related to this new problem, as I've NEVER had this problem before.


Here is what I have changed:
- New 1AWG power wire running to distro block in rear of car
- New 1AWG ground wire to chassis (I used a headlamp motor bolt---but I also tried a few others)
- Amplifier is grounded to the same spot it has been forever (used the autotek for 2 years as subwoofer amp, runs strong no problems)--I actually pulled the ground and sanded all the paint off to make it better
- Brand new ground for the headunit... I was using the stock harness ground with ZERO trouble before now.

Here is what I have tested:
- I used some 10AWG wire to create a 'common' ground between the battery/headunit/amplifier ground... no luck, no change in sound-- also I connected H/U and Amp separately to the battery negative terminal.
- I tried powering the amplifier with an external 12v power source.... no go still makes the sound
- Plugged in a walkman to the cigarette lighter, and ran RCA straight to amp.. SOUND IS GONE! -- so I thought it was the headunit...
- Pulled headunit, and hooked up to home-made bench test powersupply using old car battery... plugged RCAS from H/U straight to home theatre... no sound problems whatsoever (a slight hum when I turn up the amp, but I could cure that by simply touching my hands to the metal of the RCA connections---that may be because the amp and H/U were not sharing a common ground, as I was using the car battery to run the H/U, and my house to run the amp.
- Brought the car battery out to the car, and ran the H/U off the external battery, used the original RCAs in the car, and tricked the Autotek to turn on... CRYSTAL clear sound... I've decided to go out in the morning to AutoZone and buy a brand new GM radio harness and start from scratch, something had to be awry there...

Overall:
- Headunit worked great with internal amp, and when used with external, squealed immensely... sound was not evident all this time because the LPF of the amp cut this portion of the sound spectrum
- Headunit works great with external amp as long as I completely bypass the car's electrical system and plug RCA directly to amp (amp still using cars electrical system)
- My next step even before I buy the new harness is to get a 12v power and ground from the car, and eliminate the external car battery... while at the same time, still by-passing the GM harness. If I no longer have the noise, I will go buy another harness.
- Relieved/disappointed it's not the H/U... because if the "Best Buy Repair Center" cannot fix the problem, then they will allow me to pick out a new headunit... I don't know if there is anything better than the 8600 out yet... but it would still be interesting... (note: only ONE out of TEN best buys that I have been to even carry a SINGLE nonDVD deck that costs over $400)

Hifonics BX1605D problems in next post....

ScrapMaker

my mistake, I meant to post this here, but my browser did something, and I didn't notice the "post reply" button had morphed into the "new thread" button!

Hifonics BX1605D Problems! Woe is me.

nlghtcrawler

when i ran my two 10" MTX Audio's i had the same problem
but now i run one 12" Kicker CVR and now its very very little, dosnt really bug me, cuz my amp fan is lounder than that sound.

ScrapMaker

hrm, spending all this money on this stuff makes living with that noise not an option...

NEEDAZ

I think I go this one. Do you have/know how to use a DMM to measure resistance? If so measure the resistence from the RCA ground (outside) on the HU to the chassis of the HU.

Chevmdnss

Your amplifier ground is entirely too long if it is more than 36".

If the ignition is off, how is the amp staying on?

It sounds like a shield problem between the Headunit and RCAs.



I don't think a wiring harness is the issue here.

ScrapMaker

Tomorrow I will check with voltmeter like you say... I never thought of that.

for sure, my amplifier works perfectly... and my headunit does as well.... when I hook up the headunit to an isolated car battery on it's own... then run the RCAs to the amplifier (running off the main car battery, I get no hum!

also if I plug in a walkman to the cigarette lighter via inverter I can get a perfectly clean signal as well... but I've heard that an inverter isolates the ground from the rest of the car.

after I check with the voltmeter, I am going to pull the amp and headunit from the car, and hook them up on a 12v test bench, run power to a dist. block, and ground as well, then hook up both the amp and the headunit to each block... then run the RCAs... this way there is absolutely no chance for error... if it works perfectly, then I cannot figure it out...

I tried running RCAs outside of the vehicle just for grins, but I got nothing.

One thing that is interesting is the hum is VERY quiet with my ignition off (trick amp/headunit to come on,) and when I turn the key to 'RUN' mode, my fuel pump kicks in and I get a LOUD humming sound... definitely something going on there...

also if I have the amp hooked up to the ground and remote already... when I apply the power connection to the amp my fuel pump restarts! what gives? can a sudden draw of amperage cause the pump to restart, or should I start connecting the dots and maybe my new 1AWG wire has something to do with this?? -- (even though I've already bypassed it once via wire I ran temporarily outside the vehicle...)

this hasn't been my week... first the hifonics amp is crap, then this! arg...

my next step is to hook up my amp EXACTLY as I had it before (as a sub amp,) and see if I can or cannot hear these same noises... if I cannot hear them, then most likely they have existed the entire time I've had the headunit and I never knew... if they ARE there, then that means that my power wire is somehow causing this..

when I routed the power wire, I slid it through a wire loom that already existed going along the plastic trim under the doors.... that is pretty much the only time it runs near any vechicle wiring... should I pull it out of that loom and run it over the loom, or under the seats instead or what?

I guess first I'll try the DMM and I'll go from there...

Honestly, I've had about 6 amplifiers in different cars, and I've got the best battery, headunit, amplifier, power wire, ground wire, and RCA wire that I've EVER had in my life... and this is the only time I've ever experienced a hint of trouble with engine noise or ANY noise for that matter...
-- I didn't even have noise when I ran my first amp with a 10AWG wire going through the hood-to-door-under-seat-amplifier-setup... back in the day... and I half-expected my car to burn down at any moment!!

I spent $100 on connectors, fuse holders, a 200AMP fuse, and a dist. block... I felt really prepared this time...

*** One last thing... for anyone who can answer.... Is it possible for a headunit to work perfectly fine on a testbench, and when you get it in a real car it will continue to have problems? If so, is it possible my headunit TRUELY is damaged still? I may just have to buy some ground-loop isolators or something... but I thought the pioneer wiring harness had all those goodies, as there is a nice big box on the incoming yellow power wire going into the deck... maybe that's not what it is though?

vrtc350

iTrader: (1)

Didn't see anywhere in your posts, but do you have a filter on the power wire for the head unit? Or have you tried a filter?

Lumberjack

A filter is just a bandaid for the problem.

Check all your connections for loops. Process of elimination.

Have you tried powering up our amp without the head unit connected? Just supply the amp remote on with power to see if you get the hum through the speakers.

Check the RCA cables. Try disconnecting them as you can get a hum if they are grounded out.

Let us know what it was.

ScrapMaker

Well, if I have the RCAs disconnected from the amp, I get NO hum at all... and if I use a walkman powered off the power inverter (have not tried a direct dc-dc power supply for it yet,) it also works great with no hum.

as long as the RCAs are disconnected from the headunit, I can plug them into the amp with no problems...

What's VERY interesting, is if I have the ENTIRE wiring harness disconnected from the headunit, and I force the amp to turn on, and plug in the RCAs... I get a bad hum.... and when I touch the ground of the headunit to the actual ground, the hum gets better... but nothing I can do seems to get rid of the hum altogether.

And does anyone know if the Pioneer wiring harness has a power filter on it? Here is a picture of it...



My ACC wire also has some kind of filter, but much smaller.

ScrapMaker

oh yeah... and the wire nuts are ONLY there for testing!

NEEDAZ

SMACK (for the wire nuts...) Before you take all this time switching stuff, check the resistance from the RCA ground to the HUs chassis and post back...

ScrapMaker

okay, are you saying from the RCA ouptut of the headunit, to the headunit chassis? alright I can do that later today, but should I test the RCA ground at the pioneer harness, or at the amplifier? I guess both... they should both read just about perfect continuity...

NEEDAZ

Check from the RCA output (ground is the outside conductor) on the HU to the HU's chassis. Do this with the HU out of the car, or at least unplugged.

ScrapMaker

gotcha, on my way to go test all this stuff... let you guys know tonight..

ScrapMaker

I think NEEDAZ called it...

the internals of the deck are ruined... as there is ZERO continuity to the RCA grounds and the deck chassis, OR the real ground.

When I alligator clip the rca ground to the vehicle ground... the hum is eliminated... (at least while the car is off)

I still have a slight noise when the car is running... and that could possibly be a grounding issue... but since the deck is obviously screwed up, who knows...

I have a 4-year replacement plan through best buy... the only problem is pioneer units have to go to the bestbuy repair facility... if they cannot fix it, I get to pick a new deck... (I'd love a new one....)

Most likely they will pull it open and ni**er-rig the internals.... (if I were gonna fix it, I'd just jumper the deck internal common ground to the RCA ground...)

I hope they aren't that skilled...

With kenwood, sony, and jensen I was able to just walk into bestbuy with a broken deck and trade it for another (store credit)

I may not get another pioneer if I get to pick another... I really like that JVC KD-SHX900 or a few of the REALLY high-end panasonics that are coming out

if they TRUELY fix my headunit, I guess I'm fine with it... as it's pretty much still the best one out right now...

What do you think Bestbuy repair center will do for my deck NEEDAZ?

NEEDAZ

First, you don’t have zero continuity, you have an open. Second and most important (to me), why are you thinking of getting something new? Are there things you don’t like about the 8600? If so what? I’m thinking of getting one. Was going to get an Alpine but hate the way they go through MP3s. And the new ‘glide thingy’ is already causing problems. I really like how the 8600 goes through the MP3s.
Your HU has an open fuse. Pioneer, and others, have started using a small fuse on the RCA grounds. This protects the radio if you get a bad ground at the amp or HU. You have ground problems or this fuse wouldn’t have blown. FIX ALL YOUR GROUNDS. DO NOT PUT THE RADIO BACK IN UNTIL THEY ARE RIGHT. I say this because it seems it’s fast becoming practice by some to just jump out the small fuse with a small strand of wire. It’s better to ground the RCAs at they’re ground rather then the chassis, but using the fuse. And give the goods on the 8600.

ScrapMaker

Yeah the 8600 is a good headunit... it's the best I've ever used or seen in my lifetime.


Now I have determined that my grounds are very good... I cannot say that when bestbuy installed this headunit that my grounds were very good.

Where should I be looking for this fuse for the RCAs?

And did this fuse blow because the headunit was not grounded properly and it grounded itself through the RCAs and back to the amplifier?

Or was it the amp (highly unlikely,) not grounded properly, and power was sent through the deck RCAs.

By the way, I checked the amplifier and the RCAs are not grounded to the chassis of the amp either.

Is it not possible that this was a problem from the beginning, and since I've NEVER used the front/rear RCAs on the deck, (I literally just pulled off the plastic caps on the RCAs last week,) that I would have never known this was a problem?

ScrapMaker

And to answer your questions about the headunit itself. I'd say I have come to despise the Auto Time Alignment. It seems to ruin the sound. All my mids and highs become muddy and I lose a great deal of my channel separation.

The Auto EQ is great, and the standard EQ is awesome as well, being 13 bands and all. The only downside to the EQ is that it can only go down to 50hz, (but that's what an amplifier bass boost is for, right?)

I cannot find out how to mute the internal amplifier, unless it's automatic.

If you care about screensavers and backgrounds, then many other decks win in that area... but overall this deck is FAST and has an intuitive interface.

I feel like the "multi-function control," is not going to last very long.... think of it as a joystick that can also rotate indefinitely.

Now that my new amp will have a remote bass ****, I bet I will be adjusting my sound settings a lot less, so maybe that won't be a problem in the future.

The main thing that bothers me about the 8600 is the filesystem interface. When you are at the home screen, and you turn the ****, a list of files pop up... it ALWAYS starts at the root directory, not from the folder you are listening to (man that would sure make sense if they did this,) and also it only shows about 12 characters of the filename.... it will not display the id3 title in this view mode... if they would have just made it scroll I'd love it much more...

When I am looking through my songs, I always see this:

Project Pat - 01 - Fr
Project Pat - 02 - Bi
Project Pat - 03 - Wo

etc...

if I had one main beef.. that's it.

The second beef is that if this deck is truely broken, and there is another one out there that is better, I'd swap it if I could....

overall I'd recommend it to everyone... and I like customizing the backgrounds, but that's another area where it's a tad limited...

if you have any other questions about it, feel free to ask via PM, i've used it extensively and know just about every aspect of the unit.

Thanks for your help in this problem, and what do you think I should do to fix the deck? Is the fuse serviceable by me, or will I void the warranty?

-Steve

NEEDAZ

The fuse is in the unit, you need to send it to service. You WILL void the warranty if you take the unit apart.
And I know what you mean about the file system, but it's still the best I've seen. About your file names, I'm using CakeWalk and it doesn't use the album in the file name, just the track # and song title, so file names are shorter. But ya, the file system should go back to the song that is being played, it should give you an option in the setup as to what it displays here (file name, ID3 title) and it should scroll the highlighted selection.

NEEDAZ

And don't worry about the amps RCAs ground not being ground, it may not be. Some use diff. amps on the input for isolation.
Amd I'm still thing about an Alpine...

ScrapMaker

ah yeah, you're right about it being the best... although I was at a local audio shop the other day and they kid there was saying there was some new pioneer that was "made for mp3 navigation"... I asked him how it compared to the 8600mp, he had no idea...

here it is... I wonder how much better it is? The screen is smaller and crappier, but that's trivial to me.

8mp

ScrapMaker

this is the one that people have recommended to me...

I like the 'subwoofer' button... as that's what I've missed the most on the 8600mp...

http://www.pioneerelectronics.com/pn...874695,00.html

NEEDAZ

The DEH-P8mp is the Premier Version of the DEH-P80mp (you can play with the 80mp a Best Buy). Neat little unit, uses an internal switch mode supply to give the amp IC 18Vdc to work with. ‘60W’ output from the HU. The MP3 navigation is the same as the DEH-P8600. You don’t turn the ****, you press “LIST” and it’s the same from there. One may have an extra digit on the display though. The DEH-P7700 I THINK uses the same setup as well. I don’t like the looks through, to flashy. Both play AAC files also.

ScrapMaker

yeah I wish the 8600mp would play aac... but I don't have any

plus I was just searching mp3car.com and it turns out someone has finished up an m-bus and ip-bus adapter for a PC... so I may not care once I have a pc in the back, with 300gb of mp3s at my fingertips... the 8600 will make it easy to go through them as well.