aftermarket HU but no sound

B

BlackIceLSC

Dedicated LVC Member
Joined
Apr 9, 2004
Messages
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Location
Windsor, Ca
1993 Lincoln Mark VIII
factory JBL
3 years ago I installed a Pioneer DEH-line single-din head unit it Tommy's 93. I used a Metra wiring harness adapter, and it installed perfectly and operated totally normal.

Recently, the sound became so faint, you literally had to crank the volume up to 50 just to hear the sound.

I suspected the factory JBL amp had died, and purchased a used one from a known-good source.

it arrived and I plugged it in, and Viola, the sound was back to normal, except there was some crackling in the R/F door speaker at times.

I suspected the used(un-tested, as was fairly disclosed to me) amp might have internal problems. I opened the amp up and sure enough, a couple of the diodes had burnt connections.

Not having another amp, I purchased a "factory amp by-pass harness" from Metra. it basically plugs in to the INPUT harness at the amp and the OUTPUT harness, literally by-passing the amp all together.

result: NO SOUND
none at all. not even a mild pop, or static when tuned to a dead radio frequency. CD controls, all controls on the HU work normally, just ZERO sound. Yes, I checked to make sure the settings weren't set to "mute" or anything related to user error.
I double-checked all connections, and they are correct.
I then checked the car's fuses. I found the 20-amp Maxi-fuse for the JBL under the hood was blown and replaced that. I also checked Fuse #16 and #17 listed simply as "radio".
all fuses are good.

As I stated, this HU worked just fine before swapping the amp.
The rest of this lengthy post provides more details in hopes of answering questions, so only read on if you need more info to help. Thank you.
__________________________________________________________________

replacement amp MUST BE 93-94 only. I have 95 amps, but they have different plugs. I have no more correct amps in stock to test further.

when we took the replacement amp apart, we tried to solder the broken diode connections, but solder grounded against the amp frame and permanently damaged the amp(smoke DID come out, which is probably what blew the 20-amp Maxi fuse)

the Metra amp by-pass harness has the same (8)colored wires as the speaker harness(green, green/black, gray, gray/black, purple, purple/black, white, white/black). But one end has 10-wires coming off, which I assume are CD changer wires(pink and light blue)

I removed the original(previously working) Scosche wiring harness adapters and connected the Metra harness as a form of trouble-shooting, but that did not fix the problem.

I completely removed the after-market harness and plugged in a factory HU and still had no sound.

The 10 amp mini-fuse at the back of the Pioneer HU is not blown(checked).

Some online research indicates perhaps a grounded speaker thus changing the impedance(2 ohm vs 4 ohm?) and Pioneers will kill the signal by default if this happens.

I replaced one speaker just to check if somehow magically all speakers were blown during the attempted amp repair and resulting "smoke by solder" debacle.


any suggestions would be appreciated as we have gone from a HU that had sound, albeit faint, due to dead amp, to full sound with crackling speaker with used/replacement amp, to NO SOUND with amp by-pass harness.

Thank you.
 
well i hate to look like the ass here but gut the entire stock wiring, the after market head unit probably puts out as much power as the old amp did. id just run new wires from the radio to the speakers, and while i was in there id toss all that old jbl crap anyway. the stock system wires the "woofers" (5x7's) in series on the right side and the left, so im wondering if the HU thinks theres a short or something.

on a side note are you blackicelsc on psn? i read a post yesterday and i was sure there was someone on here with that name
 
Yes, I am the same BlackiceLSC on PSN forums. I am a GT5 addict.

as much as I totally agree with you, the car does not belong to me, so convincing the owner that the set up he had for the last 3 years is now completely worthless(you know how some folks just don't understand car repair-"it was working yesterday, what did you do? now you want me to spend more money and replace everything?'

if it were me, I'd hard-wire all new speakers, a sub and amp set up, etc.

But since his car literally sounded amazing(93-94's always sound better than 95+ with factory equipment for some reason) before the amp died, I will not easily be able to convince him he needs to go shopping for better audio equipment.
 
gotcha thought it was yours. id try another amp (again) i bet the head unit is seeing the speakers and going into protect mode

gt5 addict ehh? so that means you go to gt5 anonymous meetings then? ill add you whenever psn comes back up :(
 
A bad amp is pretty common. Putting another in is easiest.
Also, the amp by pass thing doesn't work. Just toss it.
 
chris2523 said:
A bad amp is pretty common. Putting another in is easiest.
Also, the amp by pass thing doesn't work. Just toss it.
Click to expand...

I am searching for a known good USED 93-94 JBL amp.
Thank you...I totally agree.

I also am bummed about the harness by-pass thing because so many have used one and it worked fine.
But I have a good feeling you are absolutely right.

I am going to buy a different amp when I find one. Thanks for taking the time to read my lengthy post.

Chicken...if you're a gt5 player...and you add me...as soon as PSN gets back online(hacked in to-long story...but it's been down for 10 days, killing the online play and car trading).
add me, and tell me what cars you need/want.
I've got 360+ of them. Many are not trade-able, but many are.

also, check out
http://www.mygranturismo.com

it's a cool site with many statistics, plus you can literally view other user's garage to see what they have(user input required to keep inventory-many of us have taken the time)
 
link is bad, but yeah i snooped around there (your garage) the other day. ive got pretty much everything ive looked for. only thing ive never seen was some edge camaro? at least i thought you had it. 2010 with racing stripes and gt on the side, looks like a "chrome line" but i dunno
 
I have a stupid question. The decks wire harness adapter, is it the kind that takes RCA inputs off the deck or is it speaker level?
 
Hey Craig, if the 95 has the stock tweeters, unhook those and 4 ohm should be in play. The rears would be 5 minutes of work but the doors, well, you know. It's worth a try but seriously, that JBL junk needs to come out and be replaced with something that isn't 16 years old.

Just a rewire and speaker swap isn't a lot of money. Add a nice small 4 channel amp and it would sound way better than stock. I might have an amp but it's not for the premium sound. It was for the plain jane.
 
Laser...it's speaker level wire, not RCA.
it literally has a small plug at the back of the HU that contains wires that are pre-stripped.
You butt-splice/solder those to the pre-spliced ends of the wiring harness adapter.
I've done it literally dozens of times, without incident. it's the most common "plug-n-play" way to go. It worked sweet for 3+ years until the factory amp died.

NoLIMIT....I know what is the best way to go. But the car owner(friend) just wants 'tunes' not "best sounding components available"...but at this point, he may be SOL. I could have him grab a couple pairs of 6x9's and we have enough wire at the shop to run it through and hard-wire the entire set up from battery to ears!

But my concern is perhaps somehow the HU has taken a dump(cannot find, nor do i see reference to a RESET button on this HU)

I guess we're just trying to eliminate the probably causes before throwing in the towel and just installing new speakers, new wiring from HU to speakers, and installing a decent amp and amp-power kit from battery to trunk.

amazingly, I was able to install this system in less than 30 minutes when he bought it. Just butt-spliced the corresponding wires together in the installation kit, plugged it in to the back of the Pioneer, and turned it on for amazing SQ for the ease of install...right up until the factory amp quit.

FWIW, I have a nice Pioneer in my 2000 Crown Vic I installed with a Sirius/XM modulator and new Pioneer 5x7's just this past Christmas. The problem is, I installed it quite well, and do not feel like removing my HU and plugging it in to his car to see if his HU took a dump. And if it did, what would happen to mine based on the cause of his? Know what I mean?

His Pioneer is the DEH line, and worked fine up until the whole amp re-solder debacle.

amazing how complicated this simple set up has become.

Thanks for the suggestions guys....keep 'em coming!
 
Craig,
I think I have a 93 amp in storage, collecting dust.
I might have a 93 HU not sure I would have to look "I never toss anything in the trash. :rolleyes:

If I remember right a bad HU or amp can cause the problems your having.
I'm not sure if what I have is any good, I just gave up and replaced.
If you want the stuff just let me know.
And yes its all 93 jbl stuff.
Useless to me.
 
Just try pulling the deck out far enough and disconnect the speaker harness. Take one speaker wire and hook it up to one speaker and see whatchya got. If you have 4 speakers, hook up 4 and set them in the seat just for testing.
 
Here is the reset button for a factory jbl amp.

baseball_bat.jpg
 
NoLimit95 said:
Just try pulling the deck out far enough and disconnect the speaker harness. Take one speaker wire and hook it up to one speaker and see whatchya got. If you have 4 speakers, hook up 4 and set them in the seat just for testing.
Click to expand...


i was starting to wonder if anyone would suggest this or not.


as for the amp. please stop trying to replace the amp with another factory amp. for crying out loud you have an aftermarket head unit get a real fuking amp. i know its not your car but friends dont let friends drive with stock stereo equipment. as someone stated chances are your pioneer as a better internal amp then the old factory amp did.

im curious why does everyone buy these special harnesses for these cars. you can goto walmart by a 5 dollar ford harness and your good to go.

oh and this should piss the lot of you off. but :q:q:q:q GT5 garbage ass game. FORZA OWNS BITCHES!! :)
 
ford nut said:
Craig,
I think I have a 93 amp in storage, collecting dust.
I might have a 93 HU not sure I would have to look "I never toss anything in the trash. :rolleyes:

If I remember right a bad HU or amp can cause the problems your having.
I'm not sure if what I have is any good, I just gave up and replaced.
If you want the stuff just let me know.
And yes its all 93 jbl stuff.
Useless to me.
Click to expand...


I want it.

I found out EXACTLY what is wrong, by studying the wiring diagrams...boy did I learn a lot from another member on another site.

check this out:

on 93-94, the flat "phone jack" looking connector is the INPUT.
the large jacks on the outer edges are OUTPUT.
essentially the Metra "amp bypass harness" is useless because all it does it force a u-turn, or connecting LEFT/RIGHT-FRONT/REAR speakers TO EACH OTHER!

no wonder there's no sound! the sound signals go to the back via the larger flat phone-jack looking plug end....and since that goes in to the amp, upon removal, it just sits there/......dead end!

so, there are 3 fixes:
1)replace the amp, plug in as stock and wait until that amp dies
2)somehow magically dis-assemble the phone jack end and directly tap in to the so-called "bypass" harness to send the sound back to the speakers!
3)directly wire each speaker from the HU

I am looking to go with OPTION #1 so whomever has a 93-94 JBL amp...send me an email with the subject AMP FROM LVC and your price and I'll paypal ya.

Thank you all!
 
chicken said:
yeah but that means i have to touch a microsuck system:D little billy gates can suck it
Click to expand...

trust me i never thought id be a microsoft fan either. however since the days of the first xbox they have and will always be better then sony. which sony has proven to be a lot worse of a company then microsoft.


im not a fan boy of micrsoft either trust me. im as nix as it gets too.



on topic.

try ebay im sure you can find those crap amps for cheap. by the way . have you asked the kid. why he is so hell bent on using a stock amp and not just by passing it and using the head unit or doing a rewire and a fresh system
 
Trippen Out said:
on topic.

try ebay im sure you can find those crap amps for cheap. by the way . have you asked the kid. why he is so hell bent on using a stock amp and not just by passing it and using the head unit or doing a rewire and a fresh system
Click to expand...

ebay is littered with 95+ amps.
as for "hell bent", nope...just doesn't want to throw money in to a sound system for a car he hardly drives.
cant say I blame him. it's got a $150 Pioneer HU in it. that's all...nothing wrong with spending time to make the factory system work with the HU like it has for the last 3 years.

I am the one who is spending all the time trying to diagnose the NO SOUND problem. it worked fine, then one day it didn't. $40 should have had it working again, but the used amp wasn't working right, and I decided to mess with it.

if you've ever heard a 93-94 Mark VIII with a stock JBL and a simple replacement HU, you'd be surprised at the SQ they produce. Far superior than any 95+ 'stock JBL' that's for sure.

anyway...I appreciate everybody's input in to this situation. I was trying to avoid getting another amp, but that's the road he wants to go.
I have no problem installing something aftermarket it we cant find a 93-94 JBL amp.

Hopefully the couple of PM's I sent out will net me a amp.
 
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