Kenwood DDX393 - Installation Help for noob

[LandCruisinMy93]

Spent a good part of the day checking some grounds. Found the one to the intake manifold was cracked and very corroded, so I spliced in a new section and got rid of the connector. Also found that the nut and washer on the positive stud of my alternator were corroded or damaged by excessive heat, probably caused by poor contact with the oversized wire lug I used when I upgraded my alternator. Also found that one of ground wires on the PS inner fender had busted and corroded wires, so I replaced that ring terminal. Also found that the nut on the positive stud of my aux battery terminal was loose. What a mess, but at the end of the day after all the fixes, I still have the hum/whine. I even pulled out all of the fuses, and no change, except of course when I pulled the radio fuse. I even ran a ground wire from where the amp is grounded to the extra gnd wire I tapped into that goes to the HU. Still have the hum/whine, do l'm guessing it is due to the amp for some reason. Will try the ground loop isolator as a last resort, and if that doesn't work, I will have to bypass the amp. What a cluster and waste of time...

I went through the same trouble shooting when I tried to isolate the cause of my HU doing the same thing...long story short..scrap the factory amp...it was the only thing that solved it for me.

 

[canman]

Never heard back from the installation shop regarding the ground loop isolator, so I ordered two of these today.

PAC SNI-1 RCA Ground Loop Noise Isolator at Crutchfield.ca

Also disconnected the speaker on the PS dash, and resoldered the speaker leads to my two rear door speakers. I actually still had the original door speaker on the DS rear (d'oh) thinking I had replaced it. So, I added the matching Pioneer speaker I had on the PS rear. I also extended the ground wire from the HU to the grounding point in the PS kick panel which is the same for the OEM amp. Hum/whine is still present, but I find I can crank the sound up more without clipping (typically 29-31 out of 35 max on volume control), I also moved the "center point" or whatever it is called to just in front of the DS seat as it was biased more towards the PS side. Overall the sound quality is improved due to practically no clipping.

 

[Qball]

Save yourself the headache and bypass the amp, lots of instruction and it's quite simple. I had the same issue until I bypassed the stupid thing.

 

[canman]

Save yourself the headache and bypass the amp, lots of instruction and it's quite simple. I had the same issue until I bypassed the stupid thing.

Yes, probably will soon. I'm looking at a compact Alpine unit I think someone mentioned in another thread. I also ordered the extra Metra connector needed to bylass the Amp.

 

[Qball]

Yes, probably will soon. I'm looking at a compact Alpine unit I think someone mentioned in another thread. I also ordered the extra Metra connector needed to bylass the Amp.

You don't need the amp if you are not running sub. Brow there is a all in one unit that will under the passenger seat if you remove the rear heater.

 

[canman]

After some delays the ground loop isolators arrived last week, but I just had a chance to try them this morning. Good news! They have eliminated most of the noise (say 90%) and the clipping has stopped, but there is still some distortion when volume is cranked above 30 depending on the song. There is still a bit of a "pop" when the unit is turned "on" and "off", but I can live with that for now. I doubt I will ever tell the difference when driving. Hopefully now I can close the chapter on this mod.

 

[canman]

Well, my Kenwood unit stopped working a few months ago. Just re-reading what I had done during the install. My amp has just been lying on the floor next to the kick panel for many years, and the stereo/sound would kick in and out sometimes. To solve it, I would just move the amp a bit until sound came back. So, not sure if issue is with the amp or with the head unit or maybe wiring in between. Seems the head unit should at least power up regardless of amp status, but I’ll need to check the electrical schematics later today. Will first check the much repaired wiring going into the amp.

 

[canman]

Tried resetting the head unit per the manual and no luck. Checked the power (12VDC) yellow wire to the head unit. My Fluke meter says 11.94VDC and my cheap Klein meter just jumps all over the place. I pulled the yellow wire pin from the white connector and ran a wire from the (+) post on the starter battery to the terminal on the yellow wire and the head unit booted up! That’s good, but now need to figure out why I’m not getting a real 12VDC out of that wire in the main harness that connects to the yellow wire. I believe that wire is blue with a white stripe and and single silver for. Need to dig up my electrical manual.

 

[canman]

Forgot to mention I had checked the “radio” fuse on the inside fuse panel just out of curiosity, and of course it was fine as that fuse also included other devices which still worked. After pulling out and going through the electrical schematic manual J noticed there was a dedicated radio fuse in the fuse box under the hood. That was fine as well, so it is likely the amp itself or the wiring to/from it. Will check it out later today.

 

[canman]

Some corroded terminals on the one connector. The worst is the blue/yellow wire that is the main (20A fused) power to the amp (lower left position in second pic). I’m hoping that this is the culprit, but should know shortly. Fingers crossed.

 

[canman]

Some crud that fell off the corroded connector after letting it soak in vinegar for a few hours. Lol!

 

[canman]

Found the problem. Now to see where I can find another terminal. Lol!

 

[canman]

Found the correct terminal in an old “door” lock switch I had picked up at the wreckers at some point. I think most of the interior non-sealed terminals are all the same as I had a couple others I think I got at the Lexus dealer at some point when I had a similar issue when I replaced my O2 sensors. I’ll use the one from the “door” switch as it has the correct gage of wire and a pigtail.

 

[canman]

Pics of terminals and door switch.

 

[canman]

Well, soldered in the new terminal, and also removed and cleaned the terminal next to it, and still not working. Wonder if the amp is finally toast. Just ordered the Metra 70-1761 Wiring kit from amazon.ca. Says I should get it next Thursday. I’m still going to clean up the wiring to the amp just in case there is some other loose/ broken wire(s) as it is a bit of a mess. Might also power up the head unit directly like I did previously just to see what happens.

 

[canman]

Unit works (with sound) via BT using my phone when I reconnected the power terminal on the back of the deck to the battery. Strange indeed. If I unplug the grey connector to the amp with the 20A power terminal the deck shuts off/is dead. So it would seem the amp still works. Will clean up the wiring to the deck and will try again without the direct wire to the battery.

 

[stevenmichael]

Played around some more trying to get rid of the hum, but no luck. Grounded the gnd wire to my starter battery for the front camera, but no change. Disconnected the CD player connector under the center console, still no change. Found two bare wires at the one of the OEM amp connectors including one that may have been a shield of some type as the bare section was over 1" long. Taped it up, and no change. Suspect that the OEM amp might be the culprit, as there is nothing "ON" that I can think of that might be introducing the hum. Will likely take it back to shop where I purchased the HU from to see what they think.
Also managed to play with some of the audio settings. Not sure how legit all this gimmickry is, but overall, I must say sound quality is good, but volume at highest setting seems to be less than the factory unit, which seems strange. Also, at higher volumes, the front speakers seem to get "clipped" if that is the correct word. Really like being able to stream songs from my iPad using BT, but there is a bit of lag in responsiveness. Overall, for the price, the unit is packed with lots of features, and I would recommend it to those looking for a double DIN replacement that don't need NAV (I use my iPad plus old Garmin 60CSX).

I put a kenwood ddx9903s in mine and I had the hum noise also . I had to solder each ground from the speakers wire going into the radio . I ran a wire straight from the ground bolt next to the battery and into the truck right to the radio . Ground your woofer and all speakers wire at the radio . Also ground the radio itself to the ground wire . Once you have all the grounds soldered to the wire going to the body frame the hum will go away . I put up with it for a few years because I never had time to pull the radio but I did it last month now it sounds great . I don't think any of the metal in the frame the dash is connected to the main ground of the battery . So don't use any bolts to try to make a ground . Run a line from under the hood . It sounds so good now . That huming drove me crazy . I went with the poke marine grade poke audio speakers that were sized for a direct fit in the rear speaker housing and front door fit so I could ue the factory covers . I cut out the rear passenger side panel and put a 12 inch woofer in that area and stuck the amp in the area behind the same panel just behind the back door . I still need to enclose the woofer . That's my next project . But even without it being enclosed properly it sounds pretty good .

 

[stevenmichael]

Shop wanted to install a ground loop isolator, but had none in stk. Wait and see..

Don't use a ground loop its like putting a band aid on the problem and they don't last long and you will get the huming again . ground each ground wire from the speaker as its going into the radio to a dedicated ground wire you need to add that you connect to the main body bolt that the battery is connected to . Run a good size ground wire 14 or 12 gauge to the radio and connect (solder) all the ground to that wire ,even the radio itself . Once you do this the hum will be gone .

 

[canman]

Been raining for almost 3 straight days now. Had a real problem just soldering a couple wires. Not sure what is going on these days, but I have three different soldering irons including a Wielder which is just a piece of crap. Also got small diameter welding solder, but still couldn’t get a decent joint. Ended up just crimping the last wires which were some ground wires I had run previously from the head unit and amp to the main ground point just above the amp on the PS kick panel. Still need to see if unit now works with the power from the amp after I cleaned up some of the wiring. If that doesn’t work, my plan was pull power from the CB but it doesn’t work either. D’oh!

The ground loops have worked so far, and there’re isn’t any discernible hum, but the two ground wires I ran I think helped as well IIRC. Not sure how you would run a ground wire for every speaker?

 

[stevenmichael]

Been raining for almost 3 straight days now. Had a real problem just soldering a couple wires. Not sure what is going on these days, but I have three different soldering irons including a Wielder which is just a piece of crap. Also got small diameter welding solder, but still couldn’t get a decent joint. Ended up just crimping the last wires which were some ground wires I had run previously from the head unit and amp to the main ground point just above the amp on the PS kick panel. Still need to see if unit now works with the power from the amp after I cleaned up some of the wiring. If that doesn’t work, my plan was pull power from the CB but it doesn’t work either. D’oh!

The ground loops have worked so far, and there’re isn’t any discernible hum, but the two ground wires I ran I think helped as well IIRC. Not sure how you would run a ground wire for every speaker?

You don't run a ground wire to every speaker . The speaker wire comes to the back of the radio where you plug it in . Just ground all the ground wires to the ground wire you run to the metal body screw that next to the battery .