Head Unit or wiring? (1 Viewer)

[DRTDuck]

History

A few months ago I replaced all my speakers. A few weeks later the DS rear door speaker was cutting in and out. Someone hear suggested to check for a grounding short and to also quite using the stereo until I fixed it as the whole left channel is all connected. I did find a ground short, a mounting screw was touching the sheet metal and they didn’t like each other. That seemed to fix this issue.

Current

Over the past several weeks my left channel has gotten more and more crackling noise in it. First only seemed to be on weak radio channels, then got to where it was happen with AM, FM and CD.

With all three speakers plugged in it crackles pretty bad, (have to turn it off, or turn to right channel only) apparently when more power is trying to be pushed through them, i.e. louder parts of songs, our volume turned up.

I experimented to see if I could locate it to a short again by unplugging all three of the left channel speakers in different order. I won’t list all the combinations, but the only combination that seems to be okay is with the front speaker only plugged in. It works okay, but if you turn the volume up half way or more, the crackling appears.

I am thinking the maybe the left channel in the head unit did get screwed up with the previous ground issue. At least that would be an easier fix that tracing a bunch of wires.

Yes, it’s the original head unit; no I don’t have another lying around to plug in to see if that is the issue.

Thoughts?

 

[landtank]

Sounds like the head unit. Mine is still around here somewhere.

 

[reffug]

I got an original head unit out of a 93 if your interested? Not sure what it would be worth. C-Dan any input. PM me if you want.

 

[landtank]

I got an original head unit out of a 93 if your interested? Not sure what it would be worth. C-Dan any input. PM me if you want.

off and die I got here first.

 

[reffug]

off and die I got here first.

Hey you said around here somewhere. I know where the hell mine is. right back at ya

 

[ginericLC]

Sounds like an amp issue. Replacing the headunit may or may not fix your problem. I don't have a 96 manual so i can't check the wiring harness to see what amps do what. But if you screwed up an amp, a different head unit won't help you unless you replace it with a non stock unit and bypass the amp.

So is there going to be a war between VA and MA? Not that I really care what you all do to fix your problems out there.

 

[landtank]

I found the head unit but I can definately say for sure the amp is long gone.

 

[DRTDuck]

Head unit didn't fix.

Landtank was the winner in the "shipping head unit war" got it last night. Thank you.

Installed this morning, nothing changed. Grr.

To add to my above description, I noticed this morning that the static increase with rpm acceleration. Would this indicate a ground issue?

Amp or ground issue.

If amp, I'll probalby choose a head unti that will by pass.

If ground, i guess i need to figure that our first, becasue i doubt a different head unit that by passes the OE amp would change that.


Frustrates the hell out of me, I can do a birf job, but can't figure out a damn radio!

 

[reffug]

Landtank was the winner in the "shipping head unit war" got it last night. Thank you.

Installed this morning, nothing changed. Grr.

You picked the wrong head unit..............

 

[lurker]

History

A few months ago I replaced all my speakers. A few weeks later the DS rear door speaker was cutting in and out. Someone hear suggested to check for a grounding short and to also quite using the stereo until I fixed it as the whole left channel is all connected. I did find a ground short, a mounting screw was touching the sheet metal and they didn’t like each other. That seemed to fix this issue.

Current

Over the past several weeks my left channel has gotten more and more crackling noise in it. First only seemed to be on weak radio channels, then got to where it was happen with AM, FM and CD.

With all three speakers plugged in it crackles pretty bad, (have to turn it off, or turn to right channel only) apparently when more power is trying to be pushed through them, i.e. louder parts of songs, our volume turned up.

I experimented to see if I could locate it to a short again by unplugging all three of the left channel speakers in different order. I won’t list all the combinations, but the only combination that seems to be okay is with the front speaker only plugged in. It works okay, but if you turn the volume up half way or more, the crackling appears.

I am thinking the maybe the left channel in the head unit did get screwed up with the previous ground issue. At least that would be an easier fix that tracing a bunch of wires.

Yes, it’s the original head unit; no I don’t have another lying around to plug in to see if that is the issue.

Thoughts?

Can you switch the rca cables from left to right ch. to see if the problem moves?

If not try the same idea with the amp cables.

 

[NovaFZJ80]

if it increases with accleration..grounding issue where the ground wire and power wire are too close together ? had somethign similar happen in my camry years ago...pos wire and ground wire were too close to each other...also you can my something that can reduce the whine that goes to the amp/head unit.l

 

[landtank]

Sounds like an alternator whine. I've always used a filter unit for that sort of stuff.

Rick

BTW: First thing I've won on here at it was to give something away.

 

[DRTDuck]

reffug- yeah that's what I was thinking just too to say it!!!


lurker - good idea

"Can you switch the rca cables from left to right ch. to see if the problem moves?

If not try the same idea with the amp cables."

not sure how to go about this, i have not noticed RCA cables.


Aslo, I know in the Lexus version there is an amp by the glove box, is that also true to the LC? I know there is one back by the sub, but I thought that was only for the sub, of course I may be wrong.

 

[lurker]

"not sure how to go about this, i have not noticed RCA cables."

I don't know how the speaker wires come out of the HU, so I assumed they are rca cables.

Anyway, if you can change the left and right speaker cables around then give that a try at the HU first, if the problem moves with the cables then I suspect it's the HU, if not it's something after the HU. If not then switch the cables after the amp, if it moves then it's the amp if not then it's the wires (shorting?).

I hope that makes some sort of sense?

 

[landtank]

This is a factory unit, it has no RCA cables just 1 plug. Lurker it would seem that you are not familiar with this setup and maybe confusing things a little. I understand the thought process but to put it into practice really isn't practical.

 

[lurker]

This is a factory unit, it has no RCA cables just 1 plug. Lurker it would seem that you are not familiar with this setup and maybe confusing things a little. I understand the thought process but to put it into practice really isn't practical.

I can't think of any other way to help them troubleshoot this problem.

While you are correct; this does somewhat confuse the situation, my mind set was for them to think about swapping cables and or components around. Who knows what this might lead to.

I know that some people can be intimidated by electronics, but I’ve been in the field for 25 years now and if I can think my way through $100,000,000.00 mobile telecommunication switches then a post like this might instill confidence that, yes they can do it also. Heck it's just a stereo.

Anyway I was just trying to help.

 

[cornerman]

throw the oem head unit in the closest garbage can. throw the oem amps in the garbage. throw the oem speakers in the garbage.

install aftermarket head unit, amp if you so desire, and speakers. be sure to bypass all the factory amps (run new wires). can be done for quite cheap if you do the work. i got a nice panasonic deck that plays MP3 cds and Sirrus for $250. my friend just bought a similar clarion deck for $125.

you will be much happier in the end.

here is my half finished write up: http://bushwick.com/rob/cruiser/FZJ80/stereo/

 

[landtank]

There is no reason to bypass the factory wiring unless you want to. When replacing the head unit you will use a different set of connectors which will exclude the amps that are installed in the truck. Do however disconnect the tweeters in the front if you replace the front speekers and disconnect the roof speekers if you replace the rear door speekers. These speekers are wired in parallel with the associated door speeker and will not only throw off the sound quality but change their impedance which might not work well with the new head unit.


I did however remove my factory amps as a precaution.

 

[ParadiseCruiser]

There is another issue that Rick has eluded to - and has been discussed at length here in the past - and that concerns the OEM external amp.

When you install an aftermarket head unit with an internal amp, and use the two gray connectors R1 & R3 to hook it up, you have effectively bypassed the OEM external amp.

The OEM amp, however, is still powered up whenever the the ignition is "On" or at "Acc". There is a significant potential for unexpected, and unwanted effects with this amp still connected to the speakers, humming along without an input signal.

In Rick's case, he removed it which is a good thing. Alternatively, you can unplug the power source/speakers at the amp (S11 & S12 plugs behind the glove box) and remove it from the circuit entirely. You don't need or want the output of this idling amplifier hosing up your audio.

Cheers, R -

 

[ginericLC]

There is another issue that Rick has eluded to - and has been discussed at length here in the past - and that concerns the OEM external amp.

When you install an aftermarket head unit with an internal amp, and use the two gray connectors R1 & R3 to hook it up, you have effectively bypassed the OEM external amp.

The OEM amp, however, is still powered up whenever the the ignition is "On" or at "Acc". There is a significant potential for unexpected, and unwanted effects with this amp still connected to the speakers, humming along without an input signal.

In Rick's case, he removed it which is a good thing. Alternatively, you can unplug the power source/speakers at the amp (S11 & S12 plugs behind the glove box) and remove it from the circuit entirely. You don't need or want the output of this idling amplifier hosing up your audio.

Cheers, R -

Are you sure that it powers up with the ignition? This seems very odd to me. I would think that headunit would turn the amp on when the headunit is turned on. If you bypass the wires for the OEM headunit you would also be bypassing the the amp turn on wires. Just a theory as Toyota and Pioneer have done some really screwed up things with OEM radios but I can't imagine that this is one of them. And it seems to me that if there was a situation like this it would be listed in car installer handbooks and I've never seen or heard any reference to having to unplug the amps from the harness.