no audio after battery died/recharged

I have an '04 Chrysler Pacifica with RBP radio option (AM/FM/CD/Tape), optional 6-disc CD/DVD changer, and rear-mounted video. It's all factory installed, and has all worked perfectly since new. I am the original owner.

Recently, the car sat idle for a month while I was away. When I returned, the battery was dead. I recharged it overnight, and the next morning it started without problem. The radio, however, now produces no sound. It powers up correctly, and displays station info., presets, etc, but without audio. Also, the steering wheel- mounted radio controls are now inoperative, and the radio no longer accesses the 6-disc changer/DVD system.

Fuses are good, nothing was loose or unplugged or physically damaged in any way. I had the radio bench- tested, and was told it was fine. I swapped the amp. with a used unit, and it made no difference. If anyone has any thoughts as to what else could be at fault, I'd appreciate hearing them. Thanks.

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Ray

Hmm. I know nothing about the audio system in your vehicle, but if the head and the amp both bench test as good then the logical issue is either power related (have you tested the voltage at the amp?) or a speaker is shorted putting the amp into protection mode. Also, does the vehicle have hands-free cell phone integration, so maybe it is locked into mute mode?

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Support the12volt.com

How did you bench test the radio? I am pretty sure that there is not a switched wire on that deck.

I did not personally bench-test the radio. I removed it and brought to a high-end audio shop nearby for testing. Cost me $35 to find out it wasn't the cause of the problem. That was after sourcing a replacement amplifier. At least the boneyard let me try the replacement first, so I didn't have to actually buy that to find out it wasn't the problem. I was hoping it could have been that simple. I would have gladly replaced either if one or the other turned out to be bad.

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Ray

As DYohn already asked, did you make sure the amplifier is getting power. There is at least one wire that should have constant 12 volts. It will probably be one of the larger wires in the harness.

When they tested the radio, did they let you hear it?

With apologies to DYohn - I neglected to answer his response in the correct sequence.

No, my car does not have hands-free cellphone integration, and a shorted speaker would seem unlikely since everything worked properly before the battery died.

No, I was not able to hear the radio when it was bench-tested. I took their word that they tested it properly and that it was good.

Yes, I have been able to verify that there is power at the amp. There are two connectors for the amp.; one is 18-pin, and the other is 12-pin. On the 18, I have 12V at two of the pins. Both are hot with ignition on or off.

On the 12, I have 12V on one pin with ignition on, whether the radio is on or off. Curiously, I have what appears to be 6V (honest!) on four of the pins, when both the ignition and radio are on.

I haven't been able to find a wiring diagram for this vehicle on-line yet, so I don't really know what I've found or what to do with this info. yet. At least I know I have power back to the amp.

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Ray

Do you have an old pair of computer speakers that you can sacrifice? If so, cut the 1/8 inch jack off of the cable that feeds the speakers. Strip that cable to expose the Shield and the 2 center conductors. Ground the shield to the chassis of the vehicle, and touch one of the center conductors into each pin of the harness. The radio turned on and the volume turned up a bit. If there is audio coming out of your deck you should be able to hear it out of the computer speakers. You will have to provide them with 110 volts.

There should be 8 wires with 6 volts, these are the speaker wires coming out of the amp.

Thanks for the advice, friend. I'll give that a shot today. As a clarification, I had tested the connectors while they were removed from the amplifier. I suppose that's why I only found four pins with 6V. I planned to test all the wiring with the connectors installed again today, anyway. I suspect that I'll find the other four 6V wires at that time. Thanks again.

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Ray

Update on "No Audio..." Problem:

Having searched many Forums and websites trying to get to the bottom of this problem, I was fortunate enough to hear from two gentlemen who provided me with schematics and pinout info. for my '04 Pacifica.

Armed with that info., I have been able to determine that I have all the proper voltage at both connectors to the amplifier, but only to one of the two connectors to the radio. The "Aux." connector still does not show any access to the 6-disc CD/DVD changer. Even though the radio has been given a clean bill-of-health by the audio shop that bench-tested it, it would appear that some internal circuitry within the radio may be at fault. My next step will be to try a replacement unit to see if that solves the problem.

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Ray

With those being only 6v I wonder if they are data controlled wires being a newer than 02 model car. That being the case I wonder if maybe something funky is going on with the bcm after losing power from the dead battery. If may not be sending the right info or sending it the right way anymore to the head or the amp. Data wires can do strange things when they get out of whack.

Just because you are finding wires with constant or accessory type voltage operation if I were you I would specifically identify the amp/system turn on wire and make sure it's getting power. All the voltage in the world won't help if it's not being told to turn on.

Last thing, does your amp have internal fusing? Some OEM amps do. Worth finding out and checking in lieu of trying a known good identical unit in its place.

Thanks for the thoughtful insight, friend. I appreciate your interest in helping me solve this problem.

I only posted the "Cliff Notes" version of what I've found. I had partially dismantled the amp earlier, and not finding any fuses apparent, I put it back together again. At this point, I'll take your advice and completely dismantle it to see if they've hidden a fuse somewhere in the guts of it.

There doesn't seem to be a wire that actually turns on the amp. As I've mentioned, there are a total of three wires into/out of the amp that are either 12V constant, or Acc-switched. All three have voltage. All the others are either signal in or out of the amp, and they all have voltage, too.

I honestly believe the problem is within the BCM, primarily because the steering wheel-mounted radio controls are not operational, and that's where these functions get their instructions. I thought I'd try a replacement radio since that seems to be the likely problem with the 6-CD changer, but I'm not particularly hopeful.

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Ray

I'm happy to report that this problem has finally been resolved. It turned out to be a faulty radio after all. I replaced the original with another RBP unit from a salvage yard, and everything works again. Not only does the system have sound again, but it also communicates with the 6-disc changer, and the steering wheel-mounted radio controls function again, also.

I'm guessing that the problem was in the Aux. circuitry in the original radio. Whatever it was, I'm delighted. Hope this may help someone who experiences this problem in the future. Thanks to everyone who helped me sort it out!



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Ray