JVC KD-AVX77 Popping

[DesignoSLK]

Hello All!

I just installed a new JVC KD-AVX77 in a 2000 Mercedes SLK230. I retained the factory Bose amp and used a harness from Metra (70-1786) with RCAs built onto it. The only other wires I hooked up were Ign, Bat, Gnd, Ill & Amp turn-on.

When I turn the uniy on and select sources, I get popping through the system. Also when I use the phone. I suspect it's a ground issue, but I'm using the ground that operated the OEM unit. I'm confused.

Any help would be greatly appreciated!

Thanks!

Kevin

Click to read more...

 

[DesignoSLK]

Anybody?

 

[hatedonmostly 5,000+ posts]

You are on the right track. When installing an aftermarket radio, you should never use the ground that is connected to the wiring harness.

Fix your ground and let us know what your results are. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[DesignoSLK]

Thanks Still. Before I posted this, I ran a seperate ground from the unit to the battery (-) and still got the popping.

What I've read (And my experience as an electronic technician) tells me to keep the system grounds central to one another so there is no difference in potential. According to my ohm meter readings, the OEM harness ground and amp ground are the same and I would assume the RCA grounds are too as they get their grounding from the unit itself.

Here's a thought though, the stereo ground is 20 gauge while the OEM harness ground is 22 gauge. And the jumper wire I used to go directly to the battery was also 22 gauge. Could that really be enough of a difference to create this popping?

 

[goingdef 10+ year member]

I run the same head unit and never had that problem I would suspect it has something to do with the factory amp and the fact that the HU is a 5v pre out it's high enough to where I have my gains all the way down and that's still too far up. Does the factory amp have a gain setting?

 

[goingdef 10+ year member]

Oh one other thing that has nothing to do with the problem, did you bother running the brake lead to the turn on lead so you would have all you options(dvd) without having to pull the parking brake?

 

[DesignoSLK]

I run the same head unit and never had that problem I would suspect it has something to do with the factory amp and the fact that the HU is a 5v pre out it's high enough to where I have my gains all the way down and that's still too far up. Does the factory amp have a gain setting?

I don't believe the factory amp has a gain setting, but I wasn't looking for any when I had it opened (the amp resides under the pass. side floor board.) If that's the case, I may need to install a reostat of some sort to bring the gains down. I just hate adding more "stuff" to the system. That's why I went with this unit to begin with, to get rid of extra crap, i.e. Parrot Bluetooth and Zune cassette adaptor.

Oh one other thing that has nothing to do with the problem, did you bother running the brake lead to the turn on lead so you would have all you options(dvd) without having to pull the parking brake?

Sorry, I replied before I saw your second post.
Well, sort of, I connected it to the unit ground.

 

[Wingman0121 10+ year member]

In my personal opinion it never works well when you use an aftermarket headunit with a factory amp, does it pop when you hook up speakers to the headunit's speaker outputs and the factory amp disconnected?

 

[goingdef 10+ year member]

undo it from the ground as of now it thinks the brake is never being pulled it needs to see a + to think the brake is on as for the popping I would just pull the factory amp and drop in a nice 4ch, it is a 4ch right?

 

[DesignoSLK]

In my personal opinion it never works well when you use an aftermarket headunit with a factory amp, does it pop when you hook up speakers to the headunit's speaker outputs and the factory amp disconnected?

I didn't try hooking up speakers to the HU's powered outs. I could try that, but it will have to wait a couple of days, back to work today and tomorrow (12 hr shifts).

undo it from the ground as of now it thinks the brake is never being pulled it needs to see a + to think the brake is on as for the popping I would just pull the factory amp and drop in a nice 4ch, it is a 4ch right?

So I should run it to a powered source, i.e. the Ign wire? Looking at the instructions/schematic that came with it, it appears it's looking for a ground. It works while I'm driving (listening to my Zune) but I get "No Signal" displayed. I figured that was because I don't have anything hooked up to video-in. That is a little annoying.
As for a separate amp (Not sure if it's a 4 ch or not, I only have 2 fronts w/ tweeters and 2 subs behind the seats.), that would mean replacing the factory speakers/subs as well as they are 2 ohm. I'm happy with the factory Bose system. But I'll do that if there's no other way.

 

[goingdef 10+ year member]

They will not tell you you have to read into the directions and yes to the ignition turn on lead so that it reads+ grounding it is like hooking it to nothing at all and right now it will not play dvds as for the rest of the system(speakers) you can keep those2ohms isn't a problem for most amps.

 

[krazykarl 10+ year member]

They will not tell you you have to read into the directions and yes to the ignition turn on lead so that it reads+ grounding it is like hooking it to nothing at all and right now it will not play dvds as for the rest of the system(speakers) you can keep those2ohms isn't a problem for most amps.

Don't wire the brake lead to any positive source, that will fry shit, it needs to be run to a switched negative.

 

[DesignoSLK]

Don't wire the brake lead to any positive source, that will fry shit, it needs to be run to a switched negative.

That's how I saw it and why I ran it to ground. When it wasn't hooked to anything I got the "Parking Brake" notice. Now that I have it hooked to ground, it works fine, except for the "No Signal" notice. Can anyone tell me what type of signal/voltage the video in is looking for? I'd like to get rid of the "No Signal" notice when I'm listening to my Zune.