How-To: Get a pre amp signal from OEM mid-line 6-CD stereo

QWIKWHIP

New Member
Getting a Pre Amp signal from your OEM Mid-line 6-CD stereo



First thing is first, I am in NO way responsible for anything attempted by the following information! This is done so at your own risk!



A few notes first about this project. First of all, the amp turn on signal is only 5 volts. This worked fine for my Kicker amp, but confirm that it will work with you amp first. If it does not, you will have to find another means of amp turn on outside of the OEM stereo. Also, I found that the signal produces a pretty good turn on/off thump if your amp is left on. However, if the amp turns on and off with the stereo, it does not thump at all. Lastly, I did this on a 2004 OEM mid-line 6-CD stereo. I can not say whether or not this will work on the Rockford Fosgate, or any other Nissan stereos.



OK, now for the fun stuff.



Step 1: Remove the stereo from the vehicle. I don't think I need to go into detail on how to remove the stereo. If you are going to do this, then I'm sure you know how to remove the stereo. If you don't, you may not want to attempt this project. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/002.gif' class='bbc_emoticon' alt=':smt002' />





Step 2: Now before you start tearing into the stereo, take a few minutes and get your RCA cables prepped and ready to go. I found them at Radio Shack, part #42-2358. This is a 6ft cable with an RCA jack (female end) on each side. You will need four total female jacks, however they come. With the Radio Shack ones you buy two sets and cut them in half giving you four jacks with long leads. The length you make them is up to you. I left mine about 24" long. You will need to strip back the jacket and prep the cable as shown. Be very careful, the wires are very thin and easy to break when trying to cut and strip. At this time you will also need to come up with a piece of blue amp turn on wire. About 24" is good for this also.





Step 3: Now that the stereo is out, you next have to open it up. Remove all the screws as marked. Then remove the top heat sink, next remove the back panel. The plugs on the top will come off with the back panel. Be sure to unplug the ribbon wire from the circuit board. Just carefully pull it up to unplug it. Also now would be a good time to plug in your soldering iron and get it warmed up.





Step 4: Now that the stereo is opened up, you will see the circuit board. There are three screws holding the board in. Remove them as marked. Also, there are two more ribbon wires that need to be carefully unplugged. Then just lift up slightly and carefully remove the circuit board by sliding it out the back of the stereo. Be careful not to damage anything on the board as you slide it out.





Now it's decision time:

There are two options at this point. This will depend on what your purpose will be with the stereo. If you will not be using the stock stereos speaker wires anymore, then you can remove the four capacitors making it much easier to install the RCA wires. But if you would like to retain the factory internal amp and use the speaker outputs then the capacitors will need to stay in place. You will then have to tap into the circuit board while the capacitors are in place, this will most likely have to be done from the back of the circuit board. This will be more difficult to do and I did not do it this way. You are on your own with this option. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/002.gif' class='bbc_emoticon' alt=':smt002' /> The following instructions will be the way I did it, removing the capacitors.



Step 5: OK, now that you have the circuit board out and in front of you, you need to remove the capacitors. This is basically the point of no return. To do this you will need to find the solder joints on the back side of the circuit board for each capacitor as marked. Once you have found there locations, grab one capacitor with needle nose pliers and with the soldering iron heat up the corresponding solder joints for the same capacitor and carefully remove it. Repeat this for all four capacitors as marked.







Step 6: Now that the capacitors are all removed it's time to feed all the new wires to the circuit board. First drill a 3/8" hole in the bracket as shown. Also, drill a small hole on the side for your grounds as shown. Now feed all your wires thru the hole and put a zip tie on each side. Make certain to leave plenty of wire to get to the circuit board where you will need to solder in. You can always cut any excess off. Also, now is a good time to solder the grounds. (Note: This is all four RCA grounds twisted together.)







Step 7: Next step is to solder the amp turn on lead in place. This is the easy one. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/001.gif' class='bbc_emoticon' alt=':smt038' /> Carefully solder it to the tab as shown in the picture. Make sure the wire is not touching any other tab when your done.





Step 8: Now for the fun part. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/001.gif' class='bbc_emoticon' alt=':smt003' /> With the capacitors all removed you will see two holes inside a circle where each capacitor was located. Now you want to solder the RCA wire for each cable into the hole that is closest to the big round power supply. Note: If you have color/channel specific RCA cables, make sure you solder the correct ones into it's appropriate hole. I have marked the holes you need, as well as what channel they are, on the following picture. (**Note: DO NOT solder were I have my wires! That was my first attempt and is not the correct holes!) When you solder these wires this could be tricky. Just take your time and be patient. You want to put the soldering iron on the back side of the board and melt the solder while carefully pushing the wire into the hole from the front. Make sure not to hold the soldering iron on the circuit board for too long. This could damage the board as well as other components on the board that are near by.





Step 9: Now the hard part is done. Make sure to double check all your new connections. Now put the circuit board back into the stereo making sure to put all the screws back in and plug all of the ribbon wires back in. Finish reassembling the stereo and take it out and test it in your truck. Remember to make sure you have your airbag light plugged in on the front panel before you turn on the truck or the airbag light will come on. Once you confirm that everything works you can finish installing it back into the truck and your done! Cool huh. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/004.gif' class='bbc_emoticon' alt=':smt004' />

 

DevilDawg

New Member
That is an Awsome Write Up Qwik. You made it look easy enough that even a electronic 'tard like myself might give it a go.
 

steves

New Member
:p over acheiver. I can't read PDFs from work it seems.



I usually do a "short" and a "long" version where the short version would have like the shot and words for doing the soldering.
 

steves

New Member
[quote name='jhromy']sorry steves...here is the pdf[/quote]



Credit QWIK, and add a website URL to the PDF and it will look good. I always do that in case the PDF gets passed on to someone without site knowledge.
 

jhromy

New Member
[quote name='steves'][quote name='jhromy']sorry steves...here is the pdf[/quote]



Credit QWIK, and add a website URL to the PDF and it will look good. I always do that in case the PDF gets passed on to someone without site knowledge.[/quote]



will do..ill make the changes when i get home from work
 

steves

New Member
[quote name='jhromy']ok steve I updated it, let me know if thats ok[/quote]



That certainly made it obvious!



In other news...my friend had this to say about keeping the caps:



[quote name='steves friend']Routing the wires for that would be ok since there's a convenient notch in the board, as seen on the board front.



The potential problems here are twofold.  Firstly, if you don't remove the capacitors, the signal might not be strong enough to drive the amp.  Secondly, it might be very risky soldering wire to the other side.  If you look at the board reverse, it appears as though the solder joints on that side of the board are shallow.  If the pads are large enough and strongly laminated to the board, this can be accomplished with ridiculous amounts of solder.  If not, making the attempt could delaminate traces on the board and make steves very unhappy.  



On the other hand... removing the caps doesn't have to be an unreversable process.  If they have uncommon values or are a strange type they can be saved in case you decide to undo the work.  They shouldn't need to be destroyed in the removal process.  You'd just need to document the location, polarity, and value of each cap.  Hell... there's probably room inside to leave them in there in a little baggie, complete with a diagram for where they go.[/quote]
 

QWIKWHIP

New Member
[quote name='steves'][quote name='jhromy']ok steve I updated it, let me know if thats ok[/quote]



That certainly made it obvious!



In other news...my friend had this to say about keeping the caps:



[quote name='steves friend']Routing the wires for that would be ok since there's a convenient notch in the board, as seen on the board front.



The potential problems here are twofold.  Firstly, if you don't remove the capacitors, the signal might not be strong enough to drive the amp.  Secondly, it might be very risky soldering wire to the other side.  If you look at the board reverse, it appears as though the solder joints on that side of the board are shallow.  If the pads are large enough and strongly laminated to the board, this can be accomplished with ridiculous amounts of solder.  If not, making the attempt could delaminate traces on the board and make steves very unhappy.  



On the other hand... removing the caps doesn't have to be an unreversable process.  If they have uncommon values or are a strange type they can be saved in case you decide to undo the work.  They shouldn't need to be destroyed in the removal process.  You'd just need to document the location, polarity, and value of each cap.  Hell... there's probably room inside to leave them in there in a little baggie, complete with a diagram for where they go.[/quote][/quote]



Great info steves. Tell your friend thanks. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/004.gif' class='bbc_emoticon' alt=':smt009' /> So I guess I won't worry about mine then. If the time comes to sell, I could even just throw a cheapy 4-chanel amp in. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/002.gif' class='bbc_emoticon' alt=':smt006' />
 

steves

New Member
Actually, we make experiment with this a little bit, and see if adding the preouts still leaves enough juice to run the amp, but that project is a few months off at the least!
 

Cheif

New Member
Great Work QwikWhip, WOW.



It's in the class of mods that few, if any think of, and only one goes after it.



Thanks for the Crash Course.



Cheif
 

TexasTitanXE

New Member
Very nice write-up QWIK. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/cheers.gif' class='bbc_emoticon' alt=':smt005' />



Documentation of this sort basically doubles the work that goes into a mod. - thanks for the extra effort.



Thanks to jhromy and steves for their work on the pdf file too.



Any new information/comments regarding this modification now that a few months have gone by??



Thanks, David <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/020.gif' class='bbc_emoticon' alt=':smt003' />
 

QWIKWHIP

New Member
[quote name='TexasTitanXE']Very nice write-up QWIK.  <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/cheers.gif' class='bbc_emoticon' alt=':smt003' />    



Documentation of this sort basically doubles the work that goes into a mod. - thanks for the extra effort.



Thanks to jhromy and steves for their work on the pdf file too.



Any new information/comments regarding this modification now that a few months have gone by??



Thanks, David  <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/020.gif' class='bbc_emoticon' alt=':smt010' />[/quote]



Thanks David. And no new updates, just that it's still working perfectly and I'm as happy as day one. <img src='http://www.titanspot.com/Titan/public/style_emoticons/<#EMO_DIR#>/004.gif' class='bbc_emoticon' alt=':smt004' />
 
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