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GM-Frank, ASE Master Certified
Category: Chevy
Satisfied Customers: 431
Experience:  37 Years Automotive Diagnosis and Repair. 25 Years of General Motors Dealer Experience
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2002 S-10 crue cab I hooked up a satalite antenia..rear speakers

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I have a 2002 S-10 crue cab I hooked up a satalite antenia to the radio and now the rear speakers don't work, If I turn it up all the way I can here them working alittle



Any time I run into a problem such as this, I always refer back to when it worked correctly.


Many aftermarket products simply will not function properly with the newer vehicles.

Or they will even create new problems.


If this were mine, I would remove all of the ad-ons, and see if things go back to working correctly.


I know this may seem like a somewhat simple answer, but it is exactly the way I would begin my diagnosis if the vehicle were here in front of me.


Remove the aftermarket satellite stuff, and see if the systems all again function as they were designed.


If it all works, then the satellite system is not connected correctly or the system is simply not compatible.


Have a Great Day



Customer: replied 8 years ago.

Frank I undid the Satalite antenia and put it back to stock and its the same no back speakers , Also I noticed that their is what appears to be a lamp to the right of the volume knob just under the word volume and it does not lite. Is their an amp or some thing,it does'nt lite even them the power is on


Thanks for helping me

Sincerly Steve Keel

Hi Steve,


Sorry for the delay in responding. I was actually at work when I answered, and now I'm at home.


Let me get some info from you so we can sort this out. I will get you some of the basic info that I have to work with here, and then we'll go from there.


I need to know if you check your RPO codes in either a glove compartment or center console. I'm looking for a possible UC6 or UM6 or UM7.... RPO code.


Can you tell me if you have one of these 3 listed?






I'm trying to find more.



The audio amplifier is standard on some vehicle lines but is optional on most. The radio supplies low level audio signals to the audio amplifier in order to boost the signal sent to the speakers. The amplifier present signal circuit allows the radio to recognize that an amplifier is present. Once the radio detects an audio amplifier, it will output low level audio signals. The audio amplifier on this vehicle is turned on when it receives battery voltage from the radio (when the radio is turned on) via the amplifier control circuit.


If you have an amp, I think they located it in the center console.


  1. Remove the negative battery cable.
  2. Remove the floor console from the vehicle.
  3. Remove remote CD changer, if equipped.
  4. Remove the console wiring harness from the amplifier.
  5. Remove the amplifier mounting nuts.
  6. Remove the amplifier from the mounting bracket.

Be careful about removing battery power. This can potentially lock the radio and if you don't have the unlock code, we might have difficulties unlocking.



Customer: replied 8 years ago.
The CD player is in the radio , it does have a tape deck on the floor. Also their is no fues were it says AMP
Customer: replied 8 years ago.
Frank do you know what the little round lamp by the volume knob is ?
Customer: replied 8 years ago.

Frank If I (accept) will you still help ?

Also Thanks for helping anyway...


I believe you are referring to the TheftLock light.


But if the radio is working from the front speakers and you adjust fade and hear only low volume out the rear speakers, then you may have a problem with the radio.



IMPORTANT: Read all steps before starting the procedure.

If more than 15 seconds elapse between any of the steps, the radio automatically reverts to time and you must start the procedure over from step 4.

If SEC appears on the display in step 4, the system has already been activated.

To change the code, the old code must be removed first.

In order to activate the Theftlock(TM) system, perform the following steps:

  1. Write down any number from 000 to 1999.
  2. Turn the ignition to the ACCESSORY or the RUN position.
  3. Turn the radio OFF.
  4. Press the 1 and 4 push-buttons together. Hold them down until "- - -" shows on the display.
  5. Press MN and 000 will appear on the display.
  6. Press and hold MN again until the last two digits agree with your code.
  7. Press and hold HR to make the first one or two digits agree with your code.
  8. Press the AM/FM push button after you have confirmed that the code matches the code you wrote down. If REP appears on the display, repeat steps 5 through 8.
  9. SEC will appear on the display, the radio is now operable and secured.
  10. With the ignition OFF, the Theftlock(TM) indicator flashes.


Oh yes Steve,

I'll stick with you. Let's get this resolved for ya.




OK Steve,


I have a bunch of audio info along with many schematics that will help us, but I really need to know the Option Code on your vehicle audio system.


I'm finding that if you do have an amplifier, The fuse in the Instrument Panel Fuse Block will be labeled AMPF and it will be fuse number 20 and it will be a 25amp fuse.




I see the RADIO Option is UE1 on your option label. That tells me you do have an amplifier.




Here is one other item I have run across when a radio has a very low output to the speakers. The radio is programmed for if it does or does not have an amplifier.


If somehow, during your sat antenna install, you got across something incorrectly, the radio may need to again be programmed for the correct output for with or without amplifier.


The normal radio without amp, the speaker wired go directly to the speakers from the radio.

With an amplifier, the output is programmed to a low level output from the radio to the amplifier. Then the amplifier will boost the output to the correct level.


Most likely what I would do here, since you didn't have a problem until you attempted the satellite antenna install, I would go to the back of the radio and switch the front and rear speaker wires, and check to see if the rear speakers then work, while the fronts then go low.


If you have no amplifier, then you know the problem is within the radio. If when you switch the front and rear speaker wires, you find that the rear speakers are still at a very low volume, then you know that your problem is either in the amplifier, or the rear speakers.



GM-Frank and 2 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
Frank I will check after work today


OK Steve,


Thanks for the "ACCEPT" and the bonus.


Let me know how it goes.



Customer: replied 8 years ago.
Fran kI will check when I get home


I'll try to get the wire colors and connector view on the back of your radio for you today and I'll shoot that to you.





Here's the wire colors and pin locations Steve.









This should help get us through this.



GM-Frank and 2 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.

Well Hello Frank Lets get at it if you don't mind, Ok heres what Ive found the fuse panel # XXXXX says AMPF ,25amp their is NO FUSE The three plugs all match,I'm pretty sure their is not an Amp going by the wire colors. On C2 their is not a DK BLU #17 or a DK BRN/WHT #18 on C1 their is no ORN/BLK #2 or Bare #4

On the radio It says Mod 15071662

Their is no code sticker in the center console but their is on the glove box, I didn't see any thing that said UC6 / UM8 or UM7 and nothing said RPO

It looks like their are 66 codes on the Sticker. Should I go ahead and Activate the Theftlock system as per your instructions

Thanks Steve


I wouldn't activate the theftlock.

If you have sound out the front speakers and low volume out the rears, you'll want to switch one set of front speaker wires with one set of rear speaker wires and see if the rear speakers are OK or if for some reason they are blown.


When you switch the wires, you'll know right away if the front speaker goes to really low volume and the rear speaker sounds normal, you have a problem within the radio.


If the front speaker still sounds fine after switching the wires, and the rear still has a really low volume, then you have a rear speaker problem.




So for example you would take the wires from connector C2

pull wires from Pin 18 which should be Dark Blue Positive or (+) and pull wire from C2 Pin 17 which would be Light Blue Negative and switch them with say.....Pin 3 of connector C1 Right Front Negative or (-) and pin 4 Light Green Positive.


Be sure to switch Positive speaker wires with Positive and Negative speaker wires with Negative from connector to connector.


If you do not have the ability to remove the terminals out of the connector, go back the wires far enough away from the connector so that you can easily splice them back together when you are finished.


I haven't eaten a meal as yet today, so I'm going to be away for a couple of hours.


I'll be back with you very soon.




Customer: replied 8 years ago.

I didnt get your massage but I did get the theft feature on and no speakers I will try the wires next by switching one and let you know in a little bit......

Thanks steve

Customer: replied 8 years ago.
Frank I found out that something is wrong with the back speakers, also the little fan on the radio does not work. Is their a connector for the back speakers that split them up ?


Just got back from dinner,


I believe there is a connector to the rear speakers....I'll get right back to you.



Customer: replied 8 years ago.

Looks like connector C203 Or C209 handles the rear speakers.






Here's another view of C209





This should get us there Steve.




On the fan,

we would send that out for repair if it was an issue.



Customer: replied 8 years ago.

Frank thanks I will look for it tommorw and let you know.


Customer: replied 8 years ago.

Hello Frank well this is what Iv'e found , I had the right size pin connector at work for the radio outputs so I made 2 leads and wired up 2 car speakers I had around to the rear outputs of the radio and they both worked fine. On connector C203 I found the wires for the rear speakers qand the front left speakers On C203 right side line A starting at the bottom of the connector. I hooked up a good speaker and it worked for the wires that went to that connector. I followed the wires from the back of C203 and they seam to run down upnder the dash back towards the center console. Thats as far as I can get.

Now were should I go ?

Customer: replied 8 years ago.
Frand Were are you located ?
Customer: replied 8 years ago.
Frank guss what ,I guess I should of checked this first but both back speakers are blown, I ohmed them out and they boyh are open. I hooked up my remote speaker and it works fine... Thanks A million for sticking with me.... Now what dio I do to pay you ?


Well Steve,


We were getting there. Most people don't have a test speaker.


Some stuff is easy, and some is a bit more difficult.


You have accepted my answers a couple of times, and you have provided me with a bonus....If you are enclined to offer more, it is very much appreciated and can be sent in the form of a bonus via JustAnswer.


BTW, I live in Las Vegas, NV.


I'm happy we got to the bottom of your concern. With the satellite antenna being the beginning, it send us a bit around and about, but we got there, and that's the main thing.


Take Care and Thanks in advance for any additional bonus you might consider.


Take Care



GM-Frank and 2 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
Frank I so happy with your help can we work on anouther Chev I have ?
Customer: replied 8 years ago.

Frank I will E-mail you my question tomorrow if its OK to work together again

Thans Again Steve


Yes Steve,


Thank You for being patient with me on this one. Thank You very much for the bonus and accepts.


You may request me whenever you have any questions.


Let me know when you want to get started on the Suburban.


Thanks Again