Head Unit install, no sound HELP!

[BooLeaN 10+ year member]

Ok so I recently installed a head unit in to my friends car. Previously he had a really crappy Koss deck and only 1 speaker was working, the driver's side.

Well I put in a used deck I grabbed from CCA Forums and it powered up but only sound came out of the passenger's side speaker (no speakers in the rear), so that's really weird.

Well after a minute, NOTHING came out. The deck powers up, cd plays, tuner works, but no sound comes out at all. We are getting 12 volts between the ground and power, also between the ground and accessory.

I installed 2 new speakers in the front, using the factory speaker wire, and still nothing.

I made him go out and buy a brand new deck, low and behold, NO SOUND.

So anyways, after trouble shooting for a few hours, can't see any breaks in the wires etc, i took out the deck and hooked it up to a battery in my garage, hooked it up to speakers and BAMMO it works like a charm.

So I bring it to the car and it works with an external battery hooked in to the speakers in the car, so the speakers aren't the issue ( i don't think?? ).

We ran power wires directly from the stereo to the factory battery, again, no sound but it powers up. So i unhook the negative cable from the batter, no sound, unhook the positive cable from the battery too, so only the power and ground are direct from the deck to battery, and it works again!!

As soon as I touch either the positive wire (from the car) to the battery, the stereo stays on, but sound shuts off. If I touch the negative wire (from the car) to the battery, the stereo stays on, but sound shuts off. This is all while having the power and ground go directly from teh deck to the battery.

Does anyone have a clue what could be wrong? It really makes no sense to me. The head unit clearly has power and ground. My best guess is that something in the car must be shorting out as soon as i put the car's wire back on the battery??

Any help would be greatly appreciated.

Thanks.

Craig G

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[MitchZ 10+ year member]

Sorry I kinda skimmed what you wrote but what if you rewired from each speaker to the deck, instead of using the factory wires / harnesses. Just bypass all that. Just use 16 or 18 gauge.

You can still use the factory 12volt / ignition / ground...

 

[BooLeaN 10+ year member]

Hey thanks for the input but that doesn't work. I used an external speaker wired straight to the deck as well and that would act the same way.

Thanks.

Craig G

 

[MitchZ 10+ year member]

I'm probably not helping at all but,....

Maybe try grounding the deck to the chassis closer to the deck?

or the power/ignition wire could be shorting somewhere before the fuse box.

Other than that, it really doesn't make any sense to me... //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

Have you run a wire directly from the battery to the deck / ignition? (The car battery, not your external garage battery)

The decks ignition and 12 volt wires can run on the same power supply, Im sayin' the ignition wire can be constant power. (So just run a wire from + of battery to the Ignition and 12 volt)

If thats the problem, you can just do a cheap job and rewire the back of the deck (ignition and 12v) to the steering column wires. Inline fuse of course... //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Good luck!

 

[BooLeaN 10+ year member]

Hey Thanks again for the input. I already tried the wires for power/ignition directly to the car battery, no luck but I haven't tried grounding the chassis of the deck so i'll give that a shot.

Thanks for the help!

Craig G

 

[Supergumby5000 5,000+ posts]

so you're saying with a direct connection from the HU to a battery along with aftermarket speaker wire to the speakers, there is no sound?

 

[FredS3251 10+ year member]

The speakers might be grounding out...are they touching any metal in the back...like the tension bars that go through the trunk....well actually what kind of vehicle is this I should ask first.

 

[BooLeaN 10+ year member]

It is a 1995 Civic Hatchback, there are no speakers at all in the rear and the speaker wires for the rear channels are not hooked up.

If I hook the stereo up directly to the car battery with the the car itself hooked up to the battery, there is no sound but the head unit powers up etc.

As soon as i disconnect the car itself from the car battery (using direct cables from the radio to battery for power, acc and ground) the sound comes on. If I touch either the car's positive or negative power cord to the battery itself, the sound will cut out again until i remove the car's power cord.

SOO Weird, I'm thinking it has to be some sort of short circuit or something right? But why would teh car run perfectly fine?! AHHHH my mind is blown LOL.

Thanks.

Craig G

 

[Carbon Summit]

I'm having the exact same problem. Did you ever find what was causing this?

 

[Mike465 10+ year member]

What you need to do is unplug the HU from the wiring harness. Then measure the resistance at the radio harness of each speaker. If you don't get a reading then try meatering it behind the factory harness. If you get a reading behind the factory harness then you have bad connection or the smart harness(if you used one) has come unpined. If you can meater all 4 speakers at the radio harness then the internal amp on the HU is bad. Now if you dont meater the speakers on the radio harness or behind the factory harness then you have a short some where.

 

[Fusion_FREAK 10+ year member]

You're getting power but no sound right?

Read here...

http://www.caraudio.com/forum/showthread.php?t=362207

 

[Carbon Summit]

Ok, I’ve messed with this simple install for more hours than I’ll admit at this point!! I’ll try to outline what I have and what I’ve done up to this point. Sorry it turned into a small novel but I figure the more details the better. I’m hoping someone sees the obvious I missed and this will be an easy fix.

The horror started when I decide to buy a cheap car to drive to work and save a little wear and tear on my truck and of course save gas. I purchased a 1986 Chevy Spectrum. The prior owner took out the entire stereo he had in it so I got it with cut up factory harness and that’s it.

I went to Best Buy and bought four cheap speakers and a cheap head unit. A JVC KD-G140 if that helps.

I used the battery that I took out of my camper for the winter as a power source and bench tested everything and all worked fine and went to install the system in the car.

I decided to avoid the factory harness. I taped off all the cut wires and don’t think my problem is with the harness. It isn’t hooked to a radio on one end and there are no speakers on the other end. Just wires sitting there. The two hot wires in the harness are now taped off but were hot when I taped them. My thinking there is if they were grounding out the fuse for that line would have popped so that must be ok. If I’m missing something here please let me know.

I ran new speaker wire to the four new speakers. At first when I installed the first head unit I tapped in to the hot wire attached to the cigarette lighter. It’s on the same fuse as the radio and it was conveniently located so I used it since it was switched by the ignition. I ran another wire from the fuse box that was always hot for the memory. At first I grounded the head unit underneath the dash. When the weirdness started I tried a few other spots including the negative wire that was hooked to the cigarette lighter. When I plugged in the harness to the head unit the display would work but no sound. I assume there was a problem with my quick wire job so I check everything from the harness to the speakers. Nothing was wrong.

My thought was other than the two hot wires and the ground really there should be no difference between the system sitting on my bench or in the car unless a speaker wire got nicked and was grounding out. I unhooked the two hot and ground wires and hooked them to the camper battery again leaving everything else installed in the car and all work like it should. I thought maybe I didn’t have a good ground when in the car so I messed around trying different things and in the end when the head unit is hooked to car power it wouldn’t play music but it does everything else like load the a CD, etc. I wired the head unit directly to the battery both hot and ground and the same problem. The pre amp outs work but the speaker wires don’t. If I unhook the battery from the car and wire the head unit directly to the battery it works fine.

Somewhere along the line I noticed that when I hook the antenna to the head unit it the music stops coming from the speaker wires too. The antenna goes up the windshield/door pillar and comes out a hole in the roof. I unscrewed it to inspect it thinking that it is cut somewhere and grounding out. It isn’t. The screws that attach it to the roof ground it out. If I take the screws out and pull up on it so the base isn’t touching the car and it works fine again.

I messed around trying to figure out what was going on and then the head unit wouldn’t even work when hooked directly to a battery without the car. I figured that something must have been wrong with the head unit and it finally died. When I say won’t work I mean produce sound. It always did light up and function like it should other than sound. Even the pre amp outs worked in the end just not the speaker wires.

I brought the head unit back and got another figuring the problem would be solved. Same problems with the new head unit as with the old one.

I’ve got an old Alpine amp so I got that out and hooked all the speaker wires too it and powered it with my camper battery. I used my laptop as a source and everything worked great. If I remember right if something wasn’t hooked up right the amp has a square led that usually lights up green would turn orange and shut the power off. Next I hooked the amp directly to the car’s battery with the battery connected to the car. Everything worked fine??? This is what I can’t figure out. Why will the amp work connected to the car’s battery but not the head unit? Next I hooked the head unit to the amp with the preamp outs and everything works like it should.

Everything working gave me hope so I unhooked the amp from everything and hooked the speakers back to the speaker wire outs on the head unit and…

NO SOUND!!!!!

So I’m at a loss. The amp works hooked to the cars battery but the head unit doesn’t??? I don’t want to install the amp in the car because I want a basic cheap setup that when I sell the car I just leave everything in and walk away. At this point I’m about ready to give up and a. install the amp or b. put my camper battery in the car as a second battery independent of the car and charge it from time to time. Ok, the second battery sounds like a pain so maybe I’ll just install the amp if worst comes to worst. The second battery would be nice because if I ever figure out what is causing this problem I then can just move the power and ground from the extra battery to the car battery and be done with it but if I install the amp I’ve got to rewire everything again under the dash.

Anyone have any ideas? This should have been an hour install at the extreme most but it has turned in to many hours and trips to the store. As for the suggestions the head unit doesn’t have the power ic setting and I’ve check the resistance both before I connected the speakers to the harness and after I hooked the speakers to the harness and both are good. Two head units with new harnesses so the problem isn’t with the head unit. Its something in that evil car!

 

[I Like Waffle]

you have a voltage problem, with the head unit plugged in to the factory harness meter your constant, ign, and ground wires and see that youre getting atleast 14 volts. Something must be grounding out when you turn the ignition on, probably happened when the previous owner ripped it out. Or either you have something wired wrong.

 

[Carbon Summit]

I'm not using the factory harness at all. The problem occurs if the key is turned on or off. Tried to eliminated that whole harness problem by pulling the lighter/radio fuse. I check for voltage with the fuse pulled and its zero (obviously, but figured I'd better check in case) then I put the fuse back in and the lighter and the radio hot wire only read 11.86 volts. The battery reads 12.37 volts. Remember the car has not been started in a few days and I've been messing with this so the battery is probaby down a little.

A few questions for thougth:

If the fuse is pulled from the radio harness wouldn't that eliminate the problem if it is there?

Why did the amp work but not the head unit when hooked to the battery, with the battery hooked to the car?

When I have the head unit hooked to an external battery and all works (I don't have the antenna hooked up or it wont work) why if I touch a ground wire from the car to the chassis of the head unit does it stop playing music?

 

[Carbon Summit]

I finally gave up and decided to put that old Alpine amp in since it works that way and be done with it. The amp is old and probably not work anything but I didn' t want to give someone one more reason to break into the piece of junk. The window would be worth more than the car. I usually don't lock it for just that reason.

Anyway. I mounted the amp and planned on using the speaker wire that was for the rear speakers for the front speakers since they were run anyway and just run a couple of short runs for the rear speakers. One of the wires was about four inches too short so I took the door sill cover off to pull the wire and there it was right in front of my eyes... one of the door sill clips had just nicked the wire. It was hard to tell if it was actally all the way through or not.

Even though the amp was mounted I had to know so I hooked the head unit back up and everything back the way it orignally was without the amp and hooked to the car battery and it works!!!

**** I wish I could have the hours I've put in to this project back. I check resistance on all the wires. Do you think my $14 Walmart mulitmeter isn't accurate enough to catch something like that?

Anyway mystery solved. Sorry poopy car (what my six year old son named the car) for blaming you!!!!