SOLVED! Ever think you should leave well enough alone?

I bought my 2006 BS with an aftermarket stereo in it. I investigated and deemed it "good enough." But then I wanted a rear shelf subwoofer and I got one and had to pull out the stereo to figure out how to hook it up. (Had looked at manuals etc online to see if it is all compatible- it is) Anyway I wanted to see how it was put together. So I am down a rabbit hole. The Porsche harness is unhacked but the poor adapter kit underwent the knife. The wire nut and electrical tape are also clues. BUT the thing worked great so it's not all bad. I am cleaning up the connections and getting the subwoofer connection squared away. A thread on that soon.

I often remind myself "better is the enemy of good" Unfortunately this is usually right after I've screwed something up trying to make it better when it was working fine.

LOL....it's threads like this that result in my 2008 being completely stock. It's not only "good enough" but likely way better than I can make it, most certainly myself, and even with hired help. Good luck. My life is too short to do rabbit hole stuff.

@blaster88 - Absolutely!!! But what I've found over the years is that it's certainly worth going in and proactively fixing the garbage mods/repairs that previous people may have done -- especially when people regularly butcher OEM wiring harnesses -- which can be repaired but clearly aren't easily replaced. Having learned over the years, where's what I generally now do: Remove all garbage and lazy wiring (remove too thick wires, wire nuts, ANY AND ALL electrical tape ) Redo all connections properly (take the time to solder, heat-shrink, use zip-ties, and use Tesa™ wire harness wrapping tape) For wires where voltage is an issue, I like to proactively wrap with self-binding silicone tape. That stuff is expensive, but is the bomb. For new installations that require wire tapping, ONLY use Positaps ™ (usually the red ones) going forward and avoid 3M connectors when possible. Yeah, it's a PITA. But when you're done, you'll have the peace of mind that you did it correctly and the fixes won't ground out / short / break on you. Case and point: Just recently, I had major issues with my frunk randomly opening (unsafe!) and it drove me crazy. Also, the frunk and trunk both opened at the same time. I went through the wiring diagrams, and couldn't figure it out. Well, I finally found an easily overlooked area that had electrical tape on it. I removed it, and found two spots that were shorting out on each other. Electrical tape will melt over time and will leave goo everywhere. Plus, it's a sure sign that someone hacked your car -- and Tesa tape is what is used at the factory. So when I encounter electrical tape in a vehicle, I gently chide myself for sloppy repairs in my youth or realize it's likely a crappy repair from a previous owner. Just my two cents.

I have gone in over my head many times. It’s has always worked out but not without some cursing and thinking I should have left it alone. The mod disease is tough to cure.

This is a perfect example of why I have left my aftermarket Pioneer alone for now. I see copper speaker wires peeking out the side covers already, and that tells me the Bose that the car came with is likely broken, disabled, removed, or something like what you see. That's why, yes, I have left it alone for now... but I do think about getting in there sometimes.

Working my way through this. Most of the electrical tape covered connections were at least soldered. But not that offending wire nut. Have gone through and replaced with TiConn's (there are a couple visible in the top photo). But still kind of a rat's nest. I have decided to leave well enough alone in the frunk and roll up those wires and re-velcro-wire tie them the way they were and leave them behind the plastic cover. The subwoofer is now subwoofing. A write up on that soon.

LWEA = Leave Well Enough Alone I had that in large letters on a sign in my lab at Bell Labs for a few decades. My boss had a bad habit of thinking he knew how to align complex optical devices (like gas, solid-state or liquid gas pumped lasers - I was in basic research inventing those sorts of things.. and inventing what was needed to quantify them.) I'd get something working well, often taking days to get it just right, and he could destroy that work in 10 seconds of twiddling some knobs. Luckily he left to teach at MIT (we're still friends and communicate once in a while..) These two things are an example of a butcher doing electronic work. The wire nut is just comical - the Scotch-Lok is painful. It appears to be tapping into a power line, and will damage the power line badly enough that it should be disassembled, stripped back and all soldered and shink-wrapped back together after untangling it from the rats nest. I feel for you. I had - if you check the thread on the Chinese head-unit install - a hacked audio harness, requiring me to track down one in a junkyard, bring it home and splice it into place with the remnants of the old harness - that was before I could do anything about hooking up the unit. I'm curious - that's an amp of some sort stuffed into the compartment ahead of the battery? Can you check how the audio cables going to it were routed? There is an issue with alternator whine caused by routing near the main connecting 12V line between the engine and the battery. If there was no whine in this system I'd love to know how they were routed (usual routing is through the empty grommet near the brake pedal, then behind the battery, and through the rubber grommet in the false firewall that's behind the evap-container (thing on the left of the compartment.) Thanks if you have the time..

I have my projects complete. I think I have left behind a situation that is better than it was. It simultaneously looks worse than it really is, and looks better than it really is. Stuff not really visible that makes it worse than it looks is a crap ton of electrical tape throughout. And also not visible is the adapter to the stock harness that has parts being used and other parts not. But I think there have been a couple of generations of aftermarket stereo in the car. For example, a wire that came out of the rats nest that was completely unconnected to anything is an aux cable - but it was cut off. Not attached to anything and just jammed in there. And the Scotch-Lok in question is on a ground wire, and the extra wire is also just cut off. It isn't tapping anything. And it also looks worse than it is because it worked perfectly before I got into it, so all tucked/jammed in the center stack it was out of sight out of mind. As for alternator whine - I have none. I am not sure where the wires are passing through but I will look to see what I can. There is an amp in the frunk. I don't see any filters or anything on the power wires which is typically what I would see to reduce alternator noise.

I tried filters and ground loop isolators- they make absolutely no difference. If I unplug the cables from the headunit to the amp inputs - the alternator noise goes away. I took double-shielded very high-end audio cables and then encased them in a continuous copper braid - grounded at one end (to avoid ground loops) - it helped a bit - but still not the answer. I found one thread somewhere that someone posted about moving the routing for the cables from near that main cable between the battery and alternator - and that eliminated his whine - I have reduced the whine by moving it - but it's STILL there - just enough to be REALLY annoying. I'm going to have my plugs/coils done soon and will be asking the mechanic doing it to add the factory stock alternator output capacitor to the alternator (I know it's not near the same area, but I'm hoping he can get to it easier than I could). For some reason Porsche must have decided to save $0.10/car and didn't put it on. I bought a few of them and will hopefully get to try that before too long (try to kill the whine at the source.) But it doesn't look like the cables on your setup take the same route mine did, so I'm curious if you can track down how they're routed. TIA!

I have an ATOTO HU in my Escalade and it has a ton of alternator whine using its stock Bose amp that it had with a stock Delco head unit that did not whine. But I had an Xtrons HU in my Audi with good factory style connectors with a stock Bose sound system that did not whine at all. May be just installation differences but may be design/manufacturing differences. I like my ATOTO feature set but I think replacement may be the only answer for it. however that you see a difference by moving the cables is instructive. I will see what I can see in the frunk it seems like the entry point into the cabin is more toward the passenger side at least for the RCA cables to the amp. Also I would point out that the RCA cables are rather thick I suspect they are shielded and maybe that helps on the whine prevention.

Exactly what I'm trying to determine. It is pickup by the cables - there is a simple test for that - 1 - Disconnect cables at amp end - does whine go away? 2 - Disconnect cables at headunit end - does whine go away? If #1 is true and #2 is NOT true - it's the cables picking up RF from the alternator, ie - if you can leave the cables connected to the amp, and disconnect them at the head unit, and there is still whine, the headunit and it's wiring is removed from the equation. And if you disconnect the cables at the amp end while still disconnected at the headunit end and the whine goes away - it's the cables picking up RF. As I mentioned briefly above - the cables currently in place are double-shielded from the factory. They have an inner braid wrapped around the center conductor, then another layer of thin plastic and a foil wrapping on top of that, finished by the protective plastic outside layer. These are not cheap cables - they're about as good as can be purchased. That still left me with whine, so I bought flexible copper braided shielding, and put that over the entire length of the cables, with a separate ground wire at one end - and then shrink-wrapped over that. Basically this created what's called a "Faraday" cage over the cable. It reduced the whine, but didn't totally eliminate it. I went into all this in a rather long thread here - - https://www.planet-9.com/threads/on...kers-to-a-ssp-equipped-boxster-damn-alternator-whine.254486/page-2#post-2222640

Here's what I can see There are two shielded RCA cables circled in red and yellow. The red circled is bundled with a bunch of things going through that big grommet toward the passenger side of the battery. The one in yellow goes under the battery tray and must enter the firewall back behind it as it does not exit on the driver side of the battery.

Thanks. I'm going to print that out and go look at mine tomorrow. It looks as if they pushed the signal cables (RCA cables) through some opening to the left of the big wire bundle going through the firewall? Or could this be that cable - in the green box - heading behind the battery..? EDIT - looking at it again - that's probably just the rear edge of the battery tray.. probably. I'll look tomorrow. Thanks!

Okay, belay all I said. I DO have alternator whine. I have never noticed it before and maybe I just haven't paid attention before, or maybe that wire nut was tamping it down and getting rid of it was a bad thing, or maybe Don just jinxed me. So the routing of my cables is not a help to you. BTW in the picture you posted the green box is the back of the battery tray. The double black cable is one of the RCAs and it is bundled up with the other wires and goes through the big grommet visible. The grey and black woven cable goes under the battery tray and through some other hole in the firewall.

Thanks. Saves me a bunch'o'trouble (re-routing those cables would be a PITA..) If the capacitor across the alternator output helps I'll let you know.. might get to that any week now.. (gotta call Max..)

SOLVED! It was such a little thing. A $1 sort of item. Actually - about $7 - but entirely insignifican in comparison to the small fortune and tortous work I'd spent and done trying to solve this issue. I just wasn't thinking about it in the right sequence. I thought getting rid of noise from the big cable carrying volts and lots of amps between the engine and battery (and on the engine, the alternator and starter) would involve blocking the noise from transferring by relocating audio leads that were picking it up, double-triple shielding them, adding in-line filters on the input of the aux amp that was making the noise - and more - it's all up above. That was wrong thinking. Better thinking was - how about getting rid of the noise at the source? It came to me that back in the old days - every car with a generator had a capacitor screwed to the body of the generator and connected across the output. It looked something like this: Same thing as above - different packaging. These were really needed in a generator equipped car - since the generators produced a lot of brush-sparking on the commutators, which eventually ate them up, and also caused absolute havoc with the AM radio of the era. And these were standard, made the generators last longer (less arcing) and the radios listenable (no generator sparking noise.) SO - my addled little brain started looking to see if one of these was installed on the Boxster. It's not - and that really rather pisses me off. Bosch makes these for a reason. They even have a mounting hole for a screw to hold it on the back of the alternator, and a terminal sticking out the back of the alternator to plug it into. I ordered up two different versions of the Bosch capacitor just to have a spare at hand. Googles AI story on alternator capacitors: So I'd tried adding huge capacitors (almost 0.5 farads) across the cable going to the battery up front in the frunk - with no success. What I hadn't considered was how the cable between the engine and battery was working like a broadcasting antenna - radiating that noise throughout the cabin area. Killing the noise at the end of the cable wasn't the answer - but then the damage had already been done. What had to be done was to remove the noise before it got on the cable - and that's exactly what this capacitor does. DUH. I had the Boxster in for plugs/coils, oil/filter (Pensotin 5W-40 in case you ask..) to Provost Motorsports in Bordentown NJ. Provost is a wonderful shop - mostly because of Max who runs the place (and does a lot of the wrenching). It's basically a race-car maintenance/repair shop for Mr. Provost's hobby of racing 987's - but it justifies it's existence (and I think helps pay Max's salary) by taking in repair work, and race-car setup for other aspiring drivers. Max is simply great. He has never rejected one of my ideas out of hand - he is happy to discuss the ideas and tell me what he thinks, and if I want to go ahead with something like adding an alternator capacitor to a car that didn't come with one - he was perfectly happy to help me out. It turns out getting to the back of the alternator isn't so easy since that part of it lives under the intake manifold, requiring manifold removal to get where the capacitor should have been installed by the factory. So - that was out - but - right above the alternator, bolted to the bulkhead is a large cable junction - where a heavy lead from the alternator comes together with a heavy lead going to the starter - and the end of the long cable heading to the battery is connected. All three in one spot, not difficult to get to (I have a photo of it somewhere.... I'll add it if I find it.) I suggested how about trying it there - and Max said - as he typically does - "sure!" - and he did. And the noise is gone. Dead quiet from the amplifier when it's not getting a signal. Sigh, it took much longer than it should have to come up with this solution, but I don't feel super awful about not thinking of it earlier since I see many many people having the same issue with no solution, or bizarre solutions involving sacrificing chickens and swinging them over their heads while rubbing their belly with their other hand. Or stuff equally as bizarre. I think I'm going to add SOLVED to the title of the thread - in the hopes other people don't go down the long and torturous path I did before being enlightened.. Happy-dance!

Bosch isn't putting capacitors on their alternators any more? Huh. The older ones had them, but I haven't worked on an alternator on any car newer than the 90s.

It appears not. The parts manual doesn't even list one - and if it's not in the parts manual it's not on the car..

The caps were removed many years ago, and replaced with "better" voltage regulators. I have had these fail in some of my previous cars. Originally, they were separate modules, but now they are often "part of" the alternator . In either case, I expect these can fail and result in noisier output. The battery in the car is expected to be part of the capacitance load of the car-system, so most of the car won't care, but I always wondered if this continues to happen on modern cars, and just goes undetected? If someone is interested in testing, you could try replacing it (wherever it is) and seeing if that helps? If we really want to dive in deeper, we could compare cars with an o-scope. I think I have one in the basement I can pull out if someone else has one to compare with?

My goodness - doesn't everyone have an O-scope in the basement (mine is a 650MHz HP... which hasn't been turned on in about 30 years, so it might take a few days on my Variac to bring it back to life...) At least we have cell cameras to take plot pictures - we wouldn't have to use a Polaroid scope camera.. I suspect it's undetected and Porsche is smart enough to run their signal wiring some distance from the big 12V cable that goes to the battery . It's somewhat easier to put that wiring in a good place as you're building the car, rather than trying to do it with a fully assembled, in-use car. The issue probably isn't a failing component in the alternator since this issue is mentioned, specifically for the 987 and 997 cars in several car-audio forums. That's where I found the clues to relocating the signal wiring to avoid running parallel to that power cable at any time. I can remember when things like a voltage regulator was a metal can attached to a fender inside wall in the engine compartment, controlling the Bosch generator. Then it moved to the firewall near the battery when alternators appeared, then to the back of the alternator when dedicated chips for it were devised, And finally fully integrated into the diode circuit on the back of the alternator. That's where we are now. Earlier Bosch alternators had a regulator/diode package that could be unbolted and replaced - I can't recall or find one for our cars, and from what my mechanic said - getting to it is a bit of a chore since it requires R&R of the intake manifold so most people take the opportunity to simply replace the alternator. Prices range for my Boxster from $1,700 from Porsche down to around $500 for a rebuilt by Bosch (which in my experience is just a brand new one sold as rebuilt) down to the big-box store "rebuilt" ones for $200. Pelican does show a VR/brushes unit - about $40: Anyway - as long as the whine is gone (or I can't hear it anymore - which is just as effective) - I'm happy and don't intend to explore further. Maybe sometime if I have the manifold off for other reasons I can try putting a capacitor right across the alternator output...

I guess I just assumed it was part of the VR/brush unit. Maybe I'm wrong, or maybe it is and the one on your car failed (wouldn't surprise me). I've actually got a digital automotive oscilloscope I bought off of Amazon for $65 that's pretty neat. Haven't tried it on the +12 circuits on the Cayman , though. If I have time I'll see what it looks like stock.

Either of those are possibilities.. capacitors certainly have a finite lifetime, which will undoubtedly cause issues for those of us with "older" cars as the cars pass 20 years old.. I can't imagine Bosch / Porsche spec'd more than 20 year life components when they built the multitude of modules living in our cars.. Maybe since Porsche considers any Porsche over 20 years old as "Classic" category and they start producing new parts for them we might have some hope. I can imagine Bosch doing something with a computer module that would be programmable to substitute for lots of other modules, just have plug and play snap-in connectors for it..

I figure a full-wave bridge rectifier might solve the problem as well... again, more things we could test, in theory. My car has an aftermarket Pioneer in it... but no noise... it came to me this way. It also had the Bose package, but from what I can see there are copper wires running to the speakers, so who knows what was really done. The speaker wires would likely reduce the impact of noise... that's one of many reasons I have left it alone, as the title here indicates!

The difficulty there would be finding one with a rating high enough to handle the starter current... since it would have to be in that same circuit.. As I am too at this point. It works, I don't need to prove anything to myself. There is a company that makes an in-line 100A filter for just this sort of noise (bad when using mobile radios apparently in some vehicles) - has a largish choke, a big capacitor and a zener diode that I suspect clips at around 14V (assuming the whine spikes are higher than that.) Nice device - but it costs about $400. My solution may not eliminate every bit of noise on the main line - but it eliminated enough that the amplifier is no longer bothered by it. I'll have to do a hand-test. The amplifier used to run rather warm - I wonder if that was due to the whine peaks...

Awesome. Congrats, Don! 1) Looks just like the capacitor in my R75/6 motorcycle near my points , TBH! Plus, those other photos look like they're out of my former VW bug. 2) Wondering if these have gone away partially due to the decline of AM radio - where the noise really shows up. 3) As I think I posted earlier in the thread, I did install some sort of in-line capacitor ( Amazon ) to knock out the RF interference with my backup camera -- which definitely helped. Meanwhile, that was installed close to the camera (actually behind the left taillight as that's where I tapped the reverse signal from the reverse lamp) and not at the source ( alternator ). Your solution looks so much more robust, but it's a shame that it's so inaccessible. If you have a link to the part, Don - that would be great to know if I'm deep down in that area of the car again as I'd certainly install one. Nice work!!!