saltyone

I just talked with Audiocontrol. They seem to think it may be a grounding issue with the factory installed amp. Their recommendation was to run a ground directly from the negative terminal of the battery to a central location of the car and ground everything (including factory HU and amp) at that point. Their logic is that, if this is a grounding problem, it will correct it and improve the overall system. I completely forgot about the ground on the factory amplifier...I knew everything else was grounded properly. I'm sure the shop just reconnected the factory ground on the amplifier when they reinstalled it into the signal path.

They also said that sending the signal directly to the DQL from the factory HU would not work. The tech stated that the signal from the HU would not be strong enough...it's low level and it requires a high level signal.

Replacing the factory amplifier with a small aftermarket would be a problem also. He said it would not be the preferred fix.

What say you mercman?

Jottle

This may not be a solution. I had an acura tech check the factory amp ground, and was told that it was good. Perhaps my tech messed up, but how would you ground the amp and HU all the way in the engine bay?

saltyone

You run one main ground to the battery and bring it to a central location. Everything else grounds to it. At least that's how the tech explained it. I'm no installer...just an enjoy-er.

mercman

If you look at the factory amp it is bolted to a metal bracket that is attached to the Chassis so I don’t think an extra ground will help. The impulse noise can get into the system via the 12 volt power lines, the system ground, the signal lines or the speaker wires. The first thing I would do is disconnect the AC Clutch connector and see if the clicking stops. If it does I would check the ground side of the AC clutch circuit. If Saltyone is correct and he had no click with the amp bypass harness then we might be on to something, although, this is a very sporadic complaint and it is not just the TSX premium that has it.

Saltyone,
I checked the manual for your system, It will work fine with the pre-outs from the HU (I am assuming that the speaker level inputs are balanced or ground isolated). The DQL-8 has hi impedance inputs so they won’t load the HU down. The only difference between the line out and speaker out is the drive current and a small gain increase. I don’t want to stray too far off the subject of this thread so PM me if you want the details.

Jeff

saveth

Alright i finnally found a fix for this damn snapping sound. I installed a 6amp 1000volt diode on the power lead for the ac clutch and its gone! When i find my diagram ill post it up. This fix took me 5 minutes to do on my own.

saveth

my mechanic said that the reason it happens only when the ac is switched off is because when the ac is on it creates an EMF and when the unit cycles off it creates whats known as back emf where the current flows in the opposite direction. I know their is more too it its just i cant remember it all. Anyways, the diode stops the current from flowing backwards thus stopping the snap.

Jottle

Awesome! Do you notice any other abnormalities with the diode installed? That is, do you hear any degradation in sound quality? I'm asking because if this gets rid of it completely, we can safely say its the ac/clutch and NOT the amp that's causing the issue! How can I do this myself? Saveth. I"m not technically savy with this stuff. Can you take some pictures of where the circuit is located and perhaps a link to the diode that you bought? We'd all really appreciate it! Note to everyone with a stock system: Saveth has an aftermarket amp, so this may not work for our stock amp I'll volunteer to try it asap on my '06.

saveth

Sound quality is the same as it doesnt directly affect the stereo at all. I bought my diode at an electronics store locally. I was told to get the biggest diode possible and the biggest one was 6a 1000v so its safe to say that was sufficient, it was 2 bucks. The only way you can mess up is if you install the diode backwards which is a big no no.

this is what a diode looks like:

the side with the line (this one is white, yours may be another color) is the side that connects to the positive side of the ac clutch. The other side is connected to a body ground, i used the ground the abs system uses. Ill snap some photos when i get a chance. Another piece of advice, try to do it when your motor is cold, your hands will thank you.

Jottle

Many thanks. So you just connect the diode to the positive wire and the other side to the ground wire or the actual ground bolt?

saveth

here are some pics:

http://img223.imageshack.us/i/09062009273.jpg/
http://img35.imageshack.us/i/09062009274.jpg/

Their are 2 plugs, the one on the top beside the rad is for the rad fan. If you follow those wires it will lead you to another plug a little bit lower down(both plugs are in the pic). Thats for the ac clutch. If you remove the clip holding the wire in place you can bring the ac clutch wires up to the rad which makes it a lot easier. The blue/red (my car is a canadian model but im almost positive the colors will be the same) is the wire you tap.

Jottle

Thanks for the pics. It's a little clearer. Can you maybe circle the correct plug in your first picture? You add the diode, connect it to the ac/clutch positive wire you described, then you add another wire to the other end of the diode and ground it like you show in the second picture, correct?

Jottle

Does anyone have a picture of the wiring diagram for the 06 TSX that shows the ac/clutch wire colors? I really don't want to end up messing up my car.

feuss2

iTrader: (1)

You might be able to see the colors near the relay pin...

feuss2

iTrader: (1)

Did you buy a general purpose diode, or one specifically labeled "fast recovery" diode, or "ultra fast recovery"?

Jottle

Anyone else willing to guinea pig this on an 06-08 and report? I'm too scared to mess up my car at this point

feuss2

iTrader: (1)

I think everyone with this issue is looking to you right now!

BTW, I plan to do this to my 04 just to make the electrical system a little more stable. Knowing that there is a relay abruptly turning on and off an inductive load there is definitely a negative pulse going somewhere. I would rather have a catch diode than let it propagate through the electrical system whether its audible or not!

Jottle

I am still unsure of exactly where to splice in the diode and how to ground it properly. So I would do it if i had a DIY or step by step picture process!

saveth

i didnt even know their are different kinds of diodes.

saveth

If you want to know which wire it is for sure, go get a tester light, turn your ac to Lo, Ground your tester light (i posted a picture of a ground you can use). Their are only 2 wires to test, if i remember correctly the power for the ac clutch is a lowergauge (fatter wire) Which ever wire lights up, thats your power. The only clip that matters is the one that is furthest away the one thats up close is for your rad fan.

cwinterrowd

I'll be trying a diode to see if this solves the problem on my '08 TSX. Every since I replaced the factory amp and speakers via mercman's harness and two JL HD amps, I've noticed this popping issue. I'm betting I've had the issue all along, but it was too faint to notice with the factory amp and speakers.

In fact, the amp to the sub had to be sent back to JL for repair a few weeks ago (I'm still waiting for it to be returned) - it was causing the sub to pop extremely loud, such that it felt like I was hitting stuff in the road. I'm glad it didn't destroy the subwoofer before I disconnected it! Now, I'm curious if this popping issue is to blame for that amp beginning to fail, or if it was a weak component in the amp.

Jottle

Wonderful! Please post up some pictures and a DIY for all of us who are also experiencing the problem. We'd greatly appreciate it!

cwinterrowd

I finally got around to installing the diode, and it worked!!

No more snapping/popping in the sound system when the AC compressor shuts down. I have an '08 TSX w/Navi with an upgraded sound system. Using the service manual, I confirmed that the Blue/Red wire (the middle pin in the 3 pin connector) is the one you want to tap in to (pages 21-24 and 21-60 in the service manual describe the connection):



I used a 20A, 400V rectifier (diode), stud mount. NTE Electronics, Inc. Part #NTE5917, and mounted it into a 2in x 2in heat sink since I don't really know how much heat this little beast will need to dissipate. I imagine this diode might be overkill - saveth mentions using a 6 amp, 1000 volt diode, but this was the largest diode my electronics shop had in stock.

I had to drill into the heat sink and grind away a circular section of the cooling fins so the diode would mount flush against the bottom of the heat sink. A dremel really comes in handy for a project like this!



I used a 6 inch piece of metal duct strap to build a small mounting surface, and bolted it in using two existing bolts- one that holds the ABS/VSA mechanism in place, and the other for the two ground wires just to the left of it:



The orange wire I used is 16 gauge wire. After completing the install, I took it out for an hour long sunset ride with some good classical music and I have yet to hear any more popping! For about $12 in parts and an hour under the hood, this is an excellent modification if you're noticing the popping noise.

The only thing I'm a little concerned about is condensation dripping down into the heat sink/diode from the AC coolant line that runs just above it. I oriented the fins so hopefully any water will drip out or evaporate.

By the way, you can click any of the images for a bigger version/closer look.

Jottle

Awesome! Thanks so much for the detailed explanation. I can't wait to try this on my '06 to confirm. Quick question: Are you using an aftermarket amp? If so, did you still have the snapping noise before you switched out the factory amp?

Jottle

Maybe I should read the thread! You do have an aftermarket amp Do you think any radioshack will have diodes like these? What kind should I ask for? The highest voltage handling?

cwinterrowd

Thanks for rereading. Since this mod has nothing to do directly with the sound system, I would say I did have the surge before upgrading the sound system, but there's a chance the factory amp could have been masking it, or the sound was too weak to notice. Of course, with aftermarket amps, I'm amplifying everything, including the noise in the electrical system.

The largest diode I see on Radio Shack's site is a 6A 50V diode.. it might work for you, but without measuring the surge, there's a risk it would fail and your AC would be out of service - the best case scenario is you replace a fuse, and your AC is back up and running. I don't really want to talk about worst case scenarios...


Sorry, I wasn't brave enough to create a dead short to see how it would fail when I did my install.

Another place you might consider getting a diode from is Mouser Electronics: http://www.mouser.com/Search/Refine....eyword=NTE5917

I've ordered odds and ends from them in the past and have been happy with them.

What would be really helpful is if we had someone with the gear to measure this surge and recommend a specific diode based on actual measurements.

feuss2

iTrader: (1)

Nice overkill

I have an NTE near me. They have really good stuff. For a single install, might as well go all out!

Even GM vehicles have catch diodes on their fan clutches - but the forums I found showed people replacing them...

cwinterrowd

Thanks! If $12 is going all out, it's minor compared to what an after market sound system costs.

That's very interesting. Do the forums mention what they're replacing them with? I'm curious what the originals are rated at and if they are using diodes with higher ratings when they're replacing them.

Another thought that crossed my mind was do we know the rating on the fuse that protects the AC compressor? That might give us a better idea on what size diode is reasonable for this application.

saveth

nice install cwinterrowd, its good to see this fixed it for you also.

feuss2

iTrader: (1)

All out... I doubt you needed the head sink!

Here's one of the threads I saw on the topic:

http://www.cadillacforums.com/forums...ay-does-2.html

Since alot of people aren't hearing the snapping with no doide installed, it probably doesn't take much to surpress it...

saveth

I thought the exact same thing but their is nothing wrong with being cautious.

cwinterrowd

While I tend to be overly cautious, the main reason I used a heat sink was more about giving the diode a good mounting surface than heat dissipation since it was a stud mount diode, otherwise the extra 50 cents I spent for the heat sink might qualify as "diode bling."

Peng

Hello saveth,
Did you use the actual diodes in the picture?
I did a quick search and the 1N4007 (I'm assuming the number is correct) is a 1A 1000V diode.
Thanks

saveth

no that's not the diode i used. That's just an example. I used a 6a 1000v diode and it worked for me cwinterrowd used a 20a and 400v diode and it worked for him. As long as its over 6amps and 400v i don't see why it wouldn't work.

limeybstrd

My 2006 Navi started this symptom today.

I used google search and found this thread.

Was there a fix eventually found for this issue?

Jottle

Yes. Read the posts above. I haven't installed the diode yet, but everyone who reports this symptom (and make sure it's what's being described in my original post at the top) and uses the diode seems to have the problem licked. It's not super easy if you aren't technical, but the fix does seem to work and fixes a stupid oversight on Acura's part.

limeybstrd

Thanks I will re-read this thread again. Just out of interest why would this occur out of the blue for no reason?

Perhaps you could take some pics when you do this?

mercman

The fix is to bring it in and tell them to change the AC clutch field coil assembly. This problem also happens on some Civics and it is not because Honda left the diode out to save money, if they did, than every single TSX and Civic would have a pop/click when the AC cycles, they don’t. The diode is part of the field coil assembly and on some systems is mounted to the bottom of the connector, on others it is internal. I don’t know if the diode on the TSX system is visible or not, but it is in the circuit, if it wasn’t Honda would be risking their electronics because the spike that the coil can produce can reach several thousand volts. This spike will jump the AC relay contacts and eventually cause the contacts to fail.
Since the click is not consistent over all the cars (only a few have it), and some start out good and then the clicking starts it tells me that the factory diode failing or disconnecting from the circuit. My 2006 had no spike at all and I checked several points with my oscilloscope, if it did not have a diode, or had a bad diode, I would have measured a spike.
Jeff

limeybstrd

Thanks for the explanation. Not sure if it helps, but my snapping popping occured after ( i noticed it ) Acura performed the steering hose recall.
When the AC compressor engages, for example if I press the auto button and I can simulate this everytime. I hear a slight knock / thud noise in the engine bay. Would you think this could be related as I dont remember it making this thud noise before, then again I could be wrong.

limeybstrd

Just a couple of more questions.

So, we believe this issue to be the diode that has become faulty? This diode is locate within the AC clutch assembly, are we sure there is no diode located in the fusebox for this? I guess that would have made this a lot easier.
Any pre-cautions to take when adding this diode, shall I disconnect AC relay or Battery negative?
I really dont want Acura to research my issue even though I still have a little bit of the bumper to bumper warranty left. Id sooner fix this myself that let someone else handle my vehicle.

mercman

You have to install the diode right at the AC clutch coil; if you install the diode backwards you will create a short that could damage your harness or start a fire so I advise that this mod should only be performed by someone with lots of electronics experience. Also, the diode only suppresses the spike that occurs when the AC disengages; it will not help if the snap/pop happens when the AC turns on.
Jeff