2005 OEM Infinity amp keeps frying?? any input please

Here's the story

Last week, the audio in my truck went out. I have a 2005 Dodge ram QC with Infnity 7 speaker system. The stereo in dash appeared to be fine(lights, display etc), but no audio from amp behind glove box.

Took it to the dealer, they tried to replace the radio, but still no audio. They ordered a new amp, put it in today. The dealer just called, said as soon as they connected the new amp, it fried.

So now they are ordering a new radio, and amp.

He says for troubleshooting, they checked all my aftermarket wiring(amp under seat for sub box under back seat). He says the wiring was fine. He says they were able to get audio from the NEW factory stereo to speakers by bypassing the amp.

He further claims that the old factory stereo would not pass audio to speakers when bypassing the amp.

My question is what would cause a otherwise fine stereo to suddenly quit and fry the amp in the process?? My concern is maybe the issue is not originally with the stereo at all, but the pci cluster

tia

JON

Reply to
yoyo22
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In general but not in all cases, when you have a factory amp'd system, you can not bypass the amp and get sound from the deck, as the deck does not have an internal amp. Think of a home stereo system where you have a pre-amp and an amp, same concept. So, the deck did not "quit" working, it was most likely doing what it was suppose to, but the amp was dead and unable to produce any sound.

How is the amp under the set for your subs wired? What was used for ground, power, and the audio source? Did you use a line out converter? Also, have the speakers been replaced, with what brand and ohm rating?

Right off though, I would say that you likely have a blown or shorted out speaker that is causing an omh load change that the factory amp can not handle, causing the issue you have. If you have a blown speaker, changing the deck or/and amp WILL NOT fix the problem. The reasons that the speaker would blow are simple but I will not get into all that right now.

Reply to
azwiley1

My first guess is a short circuit or mismatch of impedances. Also whithout seeing the system and how you are using it there is also a possiblty that you overheated and fried if you had it cranked a lot for a while as those amps can get pretty hot when doing this. A voltage spike can also wipe out some equipment if it is not internally protected.

----------------- TheSnoMan.com

Reply to
SnoMan

The amp under my seat is fed audio off the two front door speakers.(line level) Power is drawn direct from battery. The ground is right at the amp through floor boards. Speakers have not been replaced.

Risking embarrasment, Last week, I installed a new compressor (for air horns). When I reconnected the battery, I got a 2 second wiff of "electrical burn" I thought it was my heavily overused drill, and did not notice the stereo not working till the next day. I have been all over the truck trying to find the smell since it usually lingers. the only place I can smell anything is a slight hot smell from the factory head unit.

I'm wondering if when I reconnected the battery, I managed to create a surge big enough through the pci/pcm to toast the stereo, which then toasted the factory amp. I have no blown fuses, there are NO dtc's for anything showing, all my wiring checks out, as checked by me and the dealer. Afterwards as a precaution, I did add a incandescent light in line with my compressor relay to eat up any roaming juice when the relay activates.

I would not suppose simply reconnecting the battery, should fry anything,,, But now I'm not sure. The dealer still has my truck. They seem to be convinced the stereo toasted itself. I'm concerend because I play with a lot of accessories, and don't relish the idea of replacing the stereo everytime I disconnect the battery.

Reply to
yoyo22

Not saying that you didn't have a surge, but I would not find it likely that a surge of this magnitude would ONLY damage/fry the radio and/or amp and NOT do damage to any other electrical components in the truck. I would wager that your original factory radio is fine and only the amp is dead. The cause, more likely, though no way the only reason it could have happen, is a blown speaker(s). Though I definately want to hear what the dealer says.

The fact that you are running line level to your amp concerns me a little, as though yes the front speakers produce some bass, the signal is not that great and I would also wager that you have the bass on the deck maxed out (assuming here). Since bass is a mono signal, here is how you may want to run it. Get a line out converter, hook it to one of your front speakes, both are not needed, and run a short set of RCA's to the amp. This will allow you to turn the gain on the amp up, the bass on the deck down and you will likely be happier with the sound over all.

Also, if you have a lot of acc added on, you may also want to think about adding a second battery and an isolator.

Reply to
azwiley1

I believe I would check every place I drilled a hole on both sides of the panel drilled. It sounds like you have shorted something in the stereo system while installing the air horns. If you used wire ties you should check them as well, they may be too tight causing a short. Checking each speaker to ground may also shed some light on the situation.

beekeep

Reply to
beekeep

The horns are not a new install,, infact nothing was changed, except the compressor in the bed of the truck. Nothing was reouted newr wire in the install.

But since you suggested it,,what is the proper way to check speaker leads,,, what should ground to what, or have continuity?

Reply to
yoyo22

With your speakers nothing should go to ground, ever. Run the + off the amp to the + on the speak, the - to the - (for most sub set ups and always for regular speakers) To check the omh load of your regular speakers, in your case as you will likely have something crossed over somewhere, you will be best off to pull each speaker and using a DVO meter, set it at Ohms and measure it.

Please keep in mind that since you have not changed the factory speakers out and they are (supposed to be) running off a factory amp, there should be nothing wong with the factory speaker wiring. This means, that to check for a blown or bad speaker, you will have to do as above.

Reply to
azwiley1

For a power amp to fry, the most likely cause would be that the output to the speakers is shorted or grounded. High powered amps use a special kind of output called bridged. None of the speaker lines can go to ground with a bridged output. Disconnect te power amp and check the wireing. Also look for a shorted speaker. bg

Reply to
bg

This saga is apparently over. I was not able to get much detail from the dealer as to the original issue which took out the amp.

At this time the disposition is:

Dealer installed New Factory Radio, New factory amp(behined glovebox), and everything works fine.

They state, all wiring was double checked, (stock and aftermarket), they found no problems. They were a bit puzzled when the new replacement oem amp fried on install. They claim after doing some research, they zeroed in on the oem stereo. According to them something shorted out in the head unit, and transfered itself along the pci bus to the amp

Thanks for everyones help.. I guess me nor the dealer will ever know what caused the stereo to go, and why it affected the amp. I know they were concerned that my pci cluster may have suffered a short, so they were checkeing that, but it chekcs out fine.

Reply to
yoyo22

OMg Omg,,,, I checked out the dealer work today under my dash !!!!! They cut all the plastic out form the behind the glove box to get at the amp, without aking the dash apart. Then scraped up all my wires, and such. There is electrical tape on my air bag wires!!!!!!!! Looks they scuffed them too much, and covered it up. There is even duct tape under there hodling wires done!!!!!!!! So freaking po'd

But does anyone know the difference between the amp numbers 56043295A and suffixe's af ae ac?

Reply to
yoyo22

There aren't sufficient words to express my distain for most dealer "service departments." I'd take some good photos and contact a Dodge zone office.

Reply to
BigIronRam

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