Troubleshooting door speaker wiring - Help please?

[Wavey1]

I have a thread running about adding tweeters to my OEM door speakers,

http://www.nsxprime.com/forum/showthread.php/193776-Old-School-tweeter-add-on-to-OEM-Location-advice

but now I have a new problem. I could use some guidance to track this down. Background:

- The OEM head unit had failed before, was repaired once, finally shot craps, and has now been retrofitted by Daryl Willman. I'm in the middle of that installation.

- Before sending the head unit to Willman, the left channel was not working. I hoped the new head unit would fix that.

- Plugged the new HEAD unit in and the left channel was still out.

- I pulled all 3 speaker amps and sent to Brian K for rebuilding. Reinstalled those, checked all the wiring etc, in the Bose speaker boxes and added a pair of tweeters, wired in parallel to the wiring from the amps to the speakers. This is incidental and should not be causing the new problem, and the speakers work fine in the right channel.

- The left channel is still out. The sub and the right door are working fine.

- I swapped speaker boxes left-right, and the left speaker works fine plugged into the right door.

- I ran through the balance and fader adjustments in the new head unit. When its set full-front and full-left, I am getting a very faint sound to the left speaker. I assume this is the pre-amp signal.

All this tells me I do not have 12-volt power to the left door amp, or the ground is bad. I haven't done any further testing yet.

I doubt the amp relay is bad since the other two amps are getting power. Same thing for the fuse in the left kick panel. However I will check those before proceeding.

I guess the next step is to start checking continuity, from the relay output to the door connector, and everything in between? I'll check all the connectors I can locate too. I know there's a connector in the left kick panel; are there any others in the wiring harness between the relay and the left door?

Does all this sound like I'm on the right track?

Everything else in the electrical system is working normally. I also do not have any sound from the rear center speaker, but I'm pretty sure that's because the OEM phone was removed and the harness was cut by the PO. The speaker looks fine so I'll probably just run a new speaker wire from the sub, and abandon the factory wiring.

THANKS!

 

[jwmelvin]

An amp will not output a faint signal if it receives no power; rather it will output nothing. Sounds to me like there is a problem with the signal line to the left amp.

 

[Wavey1]

OK, thanks! I'll check the signal wires for continuity too. It's almost got to be in the wiring - I'd be really surprised if there was a problem with Willman's head unit.

When I'm checking continuity on the left door signal circuits (white wire and orange wire) I believe the harness is continuous from the head unit connector to a connector in the left footwell, where it connects to the door harness. Is this correct?

 

[NSX2398]

Remember that the wires from the head unit to the doors are just carrying 'line level' voltages which are low. It might be worth your while to buy the SOS wiring adapter to the head (the ipp-753 one) which is only $30 but which would let you swap the L/R outputs at the head so you could isolate whether the head is still bad or whether it's the wiring to the doors. The rear speaker is driven off the sub amp and takes both L & R as inputs. As with the previous poster, if it has any audio at all, it's probably not a wiring issue and you might be able to fade L/R at high volumes to see what happens. If it's louder on one than the older, that suggests to me that the head unit still has a problem .. but doesn't help on the sub amp diagnosis.

 

[jwmelvin]

Yes swapping the outputs from the head unit L/R would be useful. You can get the same adapters on eBay.

 

[Briank]

If the amp is powered you will hear a faint hissing sound from the speaker.

 

[Wavey1]

Thanks Ian, good idea. I hadn't really considered that the problem could be in the head unit - this is the retrofitted piece where Daryl replaces everything inside the cabinet with new parts from a Clarion head unit. I guess there could be an internal problem but it seems really unlikely. But I've done the fader test and I'm getting almost nothing at the left door, so ???

I think I'll first check the continuity on the line level wiring between the head unit connector and the left door connector. If that's good, I'll check for 12 volts and a good ground to the left door amp. Then I'll double-check all the pins on both sided of the connectors, make sure nothing's bent or pushed out.

If I can confirm that it's not a wiring or connector problem, it almost has to be the head unit. In that case I think I'll just contact Daryl and see what he wants to do.It would take as long to get the harness and test it myself as it would to send it back to him. This is really aggravating as I've sunk almost $1100 and many hours into this, expecting it to be a straight plug-in. Ugghh. But thanks for the help in any case, gentlemen.

- - - Updated - - -

If the amp is powered you will hear a faint hissing sound from the speaker.

With the balance full-left and the volume up, I'm pretty sure I was hearing the actual audio - words, music, etc. - but VERY faint. Weird. I'll confirm that again when I check everything else.

BTW, thanks for the quick turn-around on the amps, Brian!

 

[clutch1]

Does Daryl's piece take the factory Acura plug right into the back still, or is there an adapter to plug between the two?

As far as troubleshooting goes, a nice multimeter or O-scope will be of some help to you for this. It'll help narrow down where the issue is happening.

First, with both doors off go to the white/orange wires at the amp connector. First test the good one.. play some music at a fairly loud volume that is fairly loud the entire time. If using a multimeter set to AC Volts, make note of about how much voltage you have there across those 2 wires. Say.. .5Vac. It should become a higher number the higher you turn the volume. If using an O-scope make note of how the wave pattern looks, etc (Rap is good for this, long sweeping bass to look at) as well at the Voltage. That's your control group, your 'good'.

Now, go to the door with the issue. Meter across those same 2 wires, orange/white. If the reading matches the 'good' door, the issue is the amp or the speaker. If the reading is significantly LOWER, then the wiring/headunit is the issue. From what you've already done, it sounds like you'll find there to be minimal/no signal there on the orange/white (since swapping the 2 found the problem to be in the same place).

Next up go to your headunit connector itself and do this same test. Test the left and right front pairs of orange/white and compare. If you find that the 2 pairs are the same, the issue is in the wiring between the headunit and the door amp. If the 2 DO NOT match, and the 'bad' side is significantly lower, the issue is inside the headunit itself.

As with anything that's made one-off, it's not out of the realm of possibility that a custom built headunit may have an issue. (Even mass produced ones come DOA at work sometimes). However that's why we need to narrow it down before going from there!

 

[Wavey1]

Thanks clutch! I'll do exactly that. If I can eliminate wiring issues in the car, the head unit is definitely going back to Daryl.

He wires the Clarion guts directly to the OEM female connector at the back of the unit. There are also a separate set of RCA connectors, and connectors for a USB plug-in, an external mic and a wired remote (it comes with a wireless remote). He also wires both antennae connectors to the Clarion unit.

 

[Wavey1]

OK. I have absolutely no idea what's going on with this.

Yesterday I went through all the diagnostic processes very carefully, two times. I plugged the head unit and speakers in, turned it on, still had the problem with the left channel. With the balance set full left and the fader set on center, I could get faint audio (actual music, not just a buzz) in the left channel.

I pushed and pulled and twisted and moved every connector and harness and wire that I could reach, no change. I visually inspected both sides of all connectors and everything looked normal. The only connection I have not checked is the one by the left footwell fuse box, where the car harness connects to the left door harness.

I swapped the speakers left-right, no change, swapped them back.

I unplugged the speakers and checked the power to the amps, got about 13.5 volts both sides, with the car switched on but not running and on a battery tender. Everything good there.

I plugged everything back in and checked the line levels, per clutch1's advice, using a probe at the speaker connector. With the balance set on center and the volume up quite a bit, I was getting .3 to .5 on the left channel, and .6 to 1.5 on the right channel. That seems to verify a weak signal on the left, but it sounded much lower on the left than the numbers would suggest.

Then I checked the same thing probing the connector at the head unit. Similar results as above. That seems to verify that it's the head unit.

Just to eliminate that the car wiring harness was not the problem, I jumped directly from the line terminals at the head unit connector to the line terminals at the left door speaker, using light speaker wire. No change, also seems to verify that it's the head unit.

Before I pulled the head unit, I set everything in place and checked all the other functions, using the wireless remote. I ran through the fader, found that on full-front you get all door speakers, almost nothing from the sub speaker. On full rear you get almost nothing from the door speakers and all sub. OK, makes sense, set it on "center".

Then I ran through the balance adjustment again, and while doing that the left channel gradually started working normally! Over a period of maybe 30-60 seconds, it just "came in". I didn't move anything, not the head unit or the speakers or any connectors or wiring - I was using the remote control to adjust. It just started working. I left it on for at least a half-hour, and again pushed/pulled/twished all the connectors and harnesses, and could not get the problem to reappear. I switched it off and rechecked a couple of hours later. Everything is working normally.

So, WHAT THE #@*%? Is it possible that some electronic part "burned in" or something like that? Like I said at the start, I have almost no knowledge about electronics but I can do basic electrical diagnosis and work. I would love to button all this up and forget about it, but I'm leery that the problem will reappear. I went ahead and completed the head unit installation and buttoned up everything in the console. I'm replacing the plastic door liners next, then will reinstall the speakers (with the new tweeters added), then the door panels. I hope I don't have to pull all this apart again.

Comments/advice appreciated.

 

[jwmelvin]

Wow that is strange. Sounds like the issue was with the head unit but it's pretty mysterious. I sometimes laugh at myself about issues like that, for taking the attitude of "well, I guess it was a one-time event." Then my headlights went out (they had briefly flickered earlier) and I realized (once again) that rarely are problems so isolated and nonrecurring. (That particular issue for me was a junky fuse in my HID relay harness.) I hope your issue is permanently done though. I would make sure Daryl is aware so if it happens again he knows the history.

 

[Old Guy]

So, WHAT THE #@*%? Is it possible that some electronic part "burned in" or something like that? Like I said at the start, I have almost no knowledge about electronics but I can do basic electrical diagnosis and work. I would love to button all this up and forget about it, but I'm leery that the problem will reappear. I went ahead and completed the head unit installation and buttoned up everything in the console. I'm replacing the plastic door liners next, then will reinstall the speakers (with the new tweeters added), then the door panels. I hope I don't have to pull all this apart again.

Comments/advice appreciated.

Not likely 'burned in'. Based upon your description of the problems and your diagnostic process, the original problem was almost certainly with the head unit. I expect that the Clarion almost certainly uses a software controlled digital pot (variable resistor on a chip!) for volume and fader functions. You could have buggy firmware; but, I don't think so. More likely a bad connection, either at the circuit board level or a connector.

Contacts and bad connections can be self healing - sort of! The actual resistance of a contact can change as current flows across the contact. Once a little current starts flowing across the contact point, the resistance drops, more current flows, resistance drops some more, on and on ..... better connection. The problem is that the initial start to the process may have been caused by a bump or vibration rather that the marginal connection being fixed. As soon as you shut the power off and current flow stops, the connection may revert to its original marginal state and may or may not work the next time you power up. Checking for an internal bad connection on the wiring is feasible. Checking for a bad connection on the circuit board is really hard and absolute agony if they used SMDs on the board.

As a side note, this issue of contact resistance changing with current flow is the reason why security systems that monitor the status of a bunch of contact perimeter switches continuously flow a small amount of current through those switches when they are in the closed position. That helps to ensure reliable detection of a closed switch position.

I would be inclined to power the head unit up and down several times on the bench and perhaps shake it a bit in the hopes of disturbing the connection so that it stays in a permanently broken state. Then send the unit back to Williams for repair. It is also possible that the bad connection will stay fixed more (good) or less (bad) permanently depending on what fixed the connection in the first place. Its a crap shoot!

 

[Wavey1]

Yes, I'll be sure he's informed in case it happens again. I can't see where it could have been anything other than the head unit. The relay under the hood is for the amps, and the fuse in the left kick panel is for the head unit. The speaker amps were just rebuilt by Brian K. and both worked fine on the right channel. What else could it be? But I welcome the opinion of all the electronics experts here.

- - - Updated - - -

Thanks Old Guy - I don't even know what "burned in" means :-> I'm calling Daryl today to run through this. I'd be happy to send it back for his perusal.

Thanks for the additional info - I don't have the ability to bench-test, but I could unbolt it and shake it around a bit in the car. Of course the console is already closed up, should have waited.

EDIT: Just spoke with Daryl and his assessment is the same. Likely to recur. If it does he'll cover it indefinitely. I'm going to button up the doors and drive it, and wait and see what happens.

His original retrofit uses a harness that is internal to the head unit. It connects internally to the OEM connector on the back of the OEM head unit, then swings out the back and plugs into a connector that is part of the Clarion guts. He can send me a different connector that would eliminate that part - I'd unplug the car harness, plug this new adapter in and plug that directly into the Clarion port, all on the outside. He thinks that may be where the problem is as there's
some electronic part in that adapter (it's Bose-made BTW). If that's not it, the head unit will go back to him. Daryl's a real stand-up guy, as many others here have found.

 

[Old Guy]

Despite the personal inconvenience of the failure, its nice to have someone who stands behind their product and attempts to resolve problems. His retrofit is not a cheap solution; but, you appear to be getting what you paid for in terms of product support. People tend to under value product support in the race to the lowest price. Hope it works out well for you in the end.

 

[Wavey1]

Yep... my main concern was keeping it looking OEM and not cutting up the console, but also not getting into aftermarket amps, speakers, etc. Not a cheap solution at all, but cheaper than a total upgrade, the sound of which which I would not fully appreciate anyway, or even care about. If not for this snag it would have been as easy as it could be, and there's really no other good solution to keeping the OEM look. I'll report back after this is all resolved, which I have no doubt it will be. BTW, the simple tweeter addition sounds great so far!

 

[Wavey1]

Welll... it sat all day yesterday. I got the speakers w/tweeters reinstalled today, fired it up and everything sounds great! I went ahead and closed the doors up because I'm sure it's not a speaker or wiring problem. Not a big deal if I have to pull the head unit down the road; I can do that in about 10 minutes now. I'll repair the wiring to the rear center speaker tomorrow and I should be done. What an ordeal, took about 3X longer than anticipated.

Update: I pulled the passenger seat, pulled the carpets back expecting to find the remainders of a wiring harness that was cut when the OEM phone was removed. Nothing in sight. I traced all the way back to the floor speaker connector, nothing. The next step would have been to pull the rear center speaker housing, which requires pulling the 3 bulkhead panels, which I just replaced all the clips for. I'm out of steam on this project, so I buttoned it back up and will address it another day; I can live without the center speaker in the meantime.

RE: center speaker wiring, the diagram shows two wires (red/green and brown/black) from the floor speaker to the rear speaker. I could not see those wires at the floor connectors or in the bundle running to the rear speaker. Are they different colors? The wiring bundle running along the right side of the console contains what looks like a black antennae wire, a dark gray/blue sleeve, and a single green/yellow wire. I wonder if that sleeve contains the speaker wires?

 

[Wavey1]

Bump - anyone know where the rear center speaker wires run along the center tunnel? Left side or right side? Are they in a separate sleeve?

 

[NSX2398]

Bump - anyone know where the rear center speaker wires run along the center tunnel? Left side or right side? Are they in a separate sleeve?

It's been years since I re-did my audio but if I had to guess, I'd say right side since they go to the sub which is in the right pass footwell. If you've already got the sub exposed, you might want to trace the wires from the sub end.

 

[Wavey1]

I already had the sub reinstalled, but the 2-pin connector is visible right on top, with the two wires referenced above. Then it disappears into the harness. On the right side of the tunnel under the storage box, there's a bundle with an antennae cable, a single green /yellow wire, and a dark blue-gray tube or sleeve - I'm thinking the speaker wires are in that and wondered if anyone knew.

The weird thing is I just had the sub opened to replace the amp and everything looked good on that end. Also had the rear center speaker out while I was replacing all the clips in the bulkhead panels, and it looked good on that end too. But no sound from that speaker. The wiring diagram shows one connector in the floor harness - looks like that's somewhere in between but I haven't located it yet. The phone harness was cut somewhere when the PO removed it (I have that harness), but that looks like an overlay system and shouldn't affect this.