# Re-Grounding the Stock HU on Acura TSX (Gen 1)



## ratten46 (Nov 16, 2008)

I have the infamous alternator whine, and I'm assuming (with the limited troubleshooting I have done thus far), that the issue is my factory HU ground. I'm wondering, is there anyone with a Gen 1 TSX who has successfully grounded the factory HU? Where is the best place to tie into the ground? There's a wire going to the factory amp (which is no longer attached), that is labeled ground...I'm wondering if I can just cut into this one and re-ground it to the chassis....or do I need to connect closer to the HU?


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## bullyx2 (Jun 27, 2007)

How are you runing the signal from the OEM head unit to your JL? I'm assuming you tapped the balanced head unit output before the OEM amp. I have a 2005 TSX and had alternator whine after doing the same thing. (OEM Nav, Balanced outs to a 250/1 and 300/4, DLS components up front) Not sure if this could be your problem, but I had one of my passive crossovers inside of the center console near the OEM amp. Moving that crossover fixed my issue.


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## ratten46 (Nov 16, 2008)

Yes, I'm running the balanced output from the HU to a JL 500/5. All crossovers are active (in the amp), however, no components installed in the front. The only thing other than the HU and Amp is my ipod interface connected to the HU's aux input. I guess that could be picking up noise, but I wouldn't think that would be audible when the HU is off...or set to another source such as CD.


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## bmwproboi05 (May 3, 2009)

interestin. i didnt have that problem when i tried oem h.u for a few days.

have you tried to set the imput on the amp to high instead of low? it may helpish......


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## ratten46 (Nov 16, 2008)

Not sure it will help, but I haven't tried that yet, so I will. There's plenty of overlap between the high and low settings, but the high is a bit more difficult to get set exactly where you want it because it's a bit more sensitive to adjustments.

I still think regrounding the HU is probably the most likely candidate....just wondering where the HU is actually grounded....or should I cut the ground wire at the back of the HU harness?

Before I do anything drastic, I'm going to try to connect to the ground pin from the factory amp harness to the grounding point for my JL amp. I've read in many places that grounding the HU at the same place as the amp is a recommended troubleshooting task...I've just never had to do it before...then again, I've always just lived with alternator whine when it was present. It's taken me 20 years to get annoyed enough to try to fix it - lol. I used to just turn up the music until I couldn't hear it.


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## bmwproboi05 (May 3, 2009)

ratten46 said:


> Not sure it will help, but I haven't tried that yet, so I will. There's plenty of overlap between the high and low settings, but the high is a bit more difficult to get set exactly where you want it because it's a bit more sensitive to adjustments.
> 
> I still think regrounding the HU is probably the most likely candidate....just wondering where the HU is actually grounded....or should I cut the ground wire at the back of the HU harness?
> 
> Before I do anything drastic, I'm going to try to connect to the ground pin from the factory amp harness to the grounding point for my JL amp. I've read in many places that grounding the HU at the same place as the amp is a recommended troubleshooting task...I've just never had to do it before...then again, I've always just lived with alternator whine when it was present. It's taken me 20 years to get annoyed enough to try to fix it - lol. I used to just turn up the music until I couldn't hear it.


well. ill tell you that the ground is in there for it...itll be to a metal frame. how vauge is that? lol. joke aside. i really dont know where it it, but i do know that its in that din. if not then just cut it , or pop the pin out!


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## pentavolvo (Nov 12, 2008)

i would cut the oem ground behind headunit and ground straight to some good solid metal behind the dash, if that dont work run a ground from where the amp is grounded up to headunit and try just that

otherwise hell it could be cheap rca's or them ran in a bad spot


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## ratten46 (Nov 16, 2008)

After a bit of experimentation, I have found that the iSimple PXAMG ipod adapter is the culprit. It plugs in between the SAT receiver and the radio AUX input. The Sat plugged in by itself causes no interference, and the PXAMG without Sat causes interference (whining noise - even when the HU is powered "off").

So...what to do...the PXAMG doesn't have any separate power or ground; it pulls this from the HU or SAT. Do I find out which pin is grounded and re-ground it to the car chasis? Is there some other alternative? I've seen people referring to installing a "choke" on the power of ipod adapters. Any idea what this is, or where it's installed? I'm assuming it may be a inductor installed on the positive 12volt leads to remove high frequency oscillation?

Anyone have the pinout for this device? Advice?


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## bmwproboi05 (May 3, 2009)

on and off switch? like i said you should just pop out the ground wire an ground it somewhere else, and if it doesnt work pop the pin back in.


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## ratten46 (Nov 16, 2008)

I've resolved the alternator whine issue, or at least reduced it to the point where it's not annoying. I will document what I found as a reference to anyone who searches and finds this thread in the future.

First, the whine was caused by the iSimple PXAMG ipod interface. On the Gen 1 Acura TSX, it's connected to the SAT/Aux port on the bottom of the factory HU, and uses a pass-through "Y" adapter to allow the SAT tuner to function. The interface is passive in the regard that it gets its power and ground from the HU itself. For this reason, I didn't think it would be the problem. As soon as I unplugged the unit, the whine stopped. The sat tuner did not impact it either way.

The first thing I tried was to add a grounding point to the wiring harness. Since the SAT tuner didn't impact this, I unplugged that harness and removed the ground pin (black wire - on the TSX its pin 11 on the bottom of the HU). There happens to be a really nice grounding point with a bolt and several grounds right behind the in-dash storage compartment. I touched (well, it was more like smashed) the pin to this grounding point while listening. Impact to the whine was almost nothing.

So, I removed the ground pin (female) from the wiring harness that attaches to the SAT/AUX port on the HU. Of course, the interface wouldn't function like this, so I had to hold the pin to the ground to test. There's no before/after on this test, so be sure you know what the noise you're trying to eliminate sounds like. With this test, there was almost no alternator noise at all (maybe none, hard to tell with the engine running).

(Note: for those with a different car, your harness will likely differ. The wire you're looking for is black, and goes to pin 1 or pin 12 (depending on how you look at it) into the iSimple PXAMG unit. The key is to disconnect from the factory HU ground before re-grounding.)

I created an 18 inch wire to use as the ground, taped off the female ground pin from the SAT/AUX port harness, and returned the make gound pin to the SAT tuner. I spliced the new ground wire into the middle of the old ground wire, leaving the pins in place as mentioned above, just in case I sell my PXAMG and harness later. Everything was double-taped to avoid any accidental shorts. Then I loosened the ground bolt and added my new cable. Tighten bolt as much as possible. Plug all in, test, and return car to "what stereo equipment?" mode.


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## bmwproboi05 (May 3, 2009)

nice.let us know what comes next


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## VP Electricity (Apr 11, 2009)

Just came across this. We've had a Gen1 TSX since it came out (I'm El.duderino at Acurazine)

I've used Icelink, DICE, and USA-SPEC iPod adapters in these cars without any noise issues at all. If you have a 2005, I would expect that there is poor sound with the XM audio with that adapter, and if I'm right, you will want to get the USA SPEC. 

The DICE unit has the same issue but our 04 doesn't have XM...


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## DSmith07 (Dec 2, 2009)

maybe this video will help your problem
YouTube - Car Audio Q&A "acura tl subwoofer feedback, noise problem, amplifier questions"


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## VP Electricity (Apr 11, 2009)

Totally different systems.


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## ratten46 (Nov 16, 2008)

VP Electricity said:


> Just came across this. We've had a Gen1 TSX since it came out (I'm El.duderino at Acurazine)
> 
> I've used Icelink, DICE, and USA-SPEC iPod adapters in these cars without any noise issues at all. If you have a 2005, I would expect that there is poor sound with the XM audio with that adapter, and if I'm right, you will want to get the USA SPEC.
> 
> The DICE unit has the same issue but our 04 doesn't have XM...


I also frequent Acurazine...same user ID as here. I have an 06 without Nav, and I don't actually use the XM now that I have my ipod hooked in. The sound quality may have been affected, but it's very likely that I'll never reactivate my XM subscription. Once I got it properly grounded, my perception is that the sound quality improved, level is a little higher (louder), and the bass extension from the ipod is significantly better. I was NOT expecting these changes. I chose the iSimple because it allowed ipod charging, steering wheel controls, and text display on the HU. I've had it installed for 3 months now. I was already happy with this adapter, but now that I've fixed the ground issue, I'm thrilled. The noise didn't appear to me until I moved from the factory amp to an aftermarket (using a mercman adapter from the balanced lines). I have run all of my cables through the center console, so my IPOD lives in the top tray there. I only have to move it when I want to put different tunes on it.


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## bullyx2 (Jun 27, 2007)

Glad you got it resolved. For iPod integration in my 05, I used instructions I found on acurazine to convert the signal wires for the SAT radio to RCAs, then added a PAC 3 way line level switch to switch between SAT and 2 aux sources. I then added a female mini plug to the inside of the center console (where it is OEM on 06 and up) that connected to one pair of RCA inputs on the PAC. Instead of cutting the OEM wires, I purchased a harness from Honda that went between the head unit and the SAT input. I was able to do all of the cutting and splicing on that so I didn't touch any OEM wiring. I use a Belkin charger that has a mini output so iPod sound comes from the dock connector. Has worked well for close to 5 years with no noise, but I don't have the level of integration and control that you have. Glad you got it fixed.


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## VP Electricity (Apr 11, 2009)

ratten46 said:


> The noise didn't appear to me until I moved from the factory amp to an aftermarket (using a mercman adapter from the balanced lines). .


Why use an adapter if you used an amp with balanced input? Or is this some "don't cut factory wires" thing?


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## ratten46 (Nov 16, 2008)

Yeah, it's probably overboard with the "don't cut" thing, but that's what it is.


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