New amp smoking - HELP

[Trem]

So, I went to power up a new Pioneer GM-D9705 amp today, in 2022 F150, and within a minute, I smelled electrical overheating, and jumped out to see the amp smoking. Prior to smelling, I heard a tone over the speakers as soon as the radio powered up, with the same pitch as the characteristic "speaker wire beside battery cable" sound, but the sound gradually became lower and lower pitch until I smelled and then saw the smoke. My question is, was this amp defective, or did I do something wrong?

Per spec, I ran 4awg wire from battery, fused a few inches from the battery at 100A, and ran 4awg ground to a bolt behind back seat (I didn't scrape any paint on this, but relied on confidence from two other OEM wires being grounded here, and assume it's okay, going through the bolt threads that are in contact with body). Bought a Plug and Play harness for radio, ran signal through LC2i via rear speakers, then everything back up to the front via speed wire.

It's been a lot of years since I've messed with car audio, and hesitant to chance frying a second amp.

Speakers are,
JL sub, 8" (CP108LG-W3v3 Single 8W3v3), 4 olm, 250 RMS
Rockford Fosgate front/rear, think around 60-80 RMS.

Amp is Pioneer GM-D9705, 75x4 and 350x1, all at 4 olm.

So did I do something wrong here? Killin me, after all the hours and money and time spent.

Thanks

Click to read more...

 

[1aespinoza 10+ year member]

Thanks

I see the ground may have been an issue, but you were not pushing the amp hard. Were the Fosgate speakers connected to the amp with new wire or the OEM wire?

 

[Trem]

I see the ground may have been an issue, but you were not pushing the amp hard. Were the Fosgate speakers connected to the amp with new wire or the OEM wire?

Thanks @1aespinoza . I used new speed wire to go from amp to the Plug and Play harness behind radio, which then connected to the OEM wiring for the front/rear speakers.

 

[hispls 5,000+ posts]

A speaker wire shorted to ground could cause something like what you described as could failing/shorting RCA or bad RCA signal. Double check anything you can see or access and do polish the paint off of that ground spot on general principal. If you can warranty/swap that amp do yourself a favor and spend a few bucks on one of those little inline fuse holders at the parts store and some 5A fuses to run the amp power through while you test and troubleshoot. Still be ready to shut it down immediately if you hear anything unusual but 5A fuse should open before the amp can hurt itself. Try connecting just the amp to power, ground and REM first then test, then connect speaker wires and test, then connect the RCAs and test again.

 

[Trem]

A speaker wire shorted to ground could cause something like what you described as could failing/shorting RCA or bad RCA signal. Double check anything you can see or access and do polish the paint off of that ground spot on general principal. If you can warranty/swap that amp do yourself a favor and spend a few bucks on one of those little inline fuse holders at the parts store and some 5A fuses to run the amp power through while you test and troubleshoot. Still be ready to shut it down immediately if you hear anything unusual but 5A fuse should open before the amp can hurt itself. Try connecting just the amp to power, ground and REM first then test, then connect speaker wires and test, then connect the RCAs and test again.

Really appreciate the advice @hispls. Will run through all of the above as soon as I have time. Pending a warranty attempt with seller of amp. Thanks!!

 

[1aespinoza 10+ year member]

Thanks @1aespinoza . I used new speed wire to go from amp to the Plug and Play harness behind radio, which then connected to the OEM wiring for the front/rear speakers.

This is not a dig but just a question for clarification; did you leave the high speaker outputs from the radio disconnected from the P&P harness?

 

[Trem]

This is not a dig but just a question for clarification; did you leave the high speaker outputs from the radio disconnected from the P&P harness?

Haha, no offense taken. I did cut them, yep, with high outputs for rear speakers going to LC2i, then RCA from there to amp, then speed wire (8 wire) back up to harness and out to all four speakers. Which is to say, I did also cut and splice the harness wires for the fronts.

Not sure how any of the wiring could have been nicked or shorted, per above suggestion, as the speed wire is pretty heavy duty insulation. And the RCA's only run about a foot, between LC2i and amp (I ran a PnP 17ft harness to back of truck, for high output, which was taped all the way, and I ran it through split-loom below kick panels).

 

[1aespinoza 10+ year member]

Haha, no offense taken. I did cut them, yep, with high outputs for rear speakers going to LC2i, then RCA from there to amp, then speed wire (8 wire) back up to harness and out to all four speakers. Which is to say, I did also cut and splice the harness wires for the fronts.

Not sure how any of the wiring could have been nicked or shorted, per above suggestion, as the speed wire is pretty heavy duty insulation. And the RCA's only run about a foot, between LC2i and amp (I ran a PnP 17ft harness to back of truck, for high output, which was taped all the way, and I ran it through split-loom below kick panels).

Kudos, you are thorough with your install. A simple test before removing any trim or panels would be to check resistance of the speakers at the amp. Disconnect them all and prevent them from touching each other or any metal. Test each pair and if all Ohm's out, test each wire against ground. Then maybe test each wire against each other.

 

[Trem]

Kudos, you are thorough with your install. A simple test before removing any trim or panels would be to check resistance of the speakers at the amp. Disconnect them all and prevent them from touching each other or any metal. Test each pair and if all Ohm's out, test each wire against ground. Then maybe test each wire against each other.

Very good call! I disconnected the harness through the top dash panel (tight squeeze getting hand down in there to connect/disconnect, but doable), but will throw meter on everything next weekend. The seller is going to refund the amp, which is nice, and I'll order another one.

Yeah, after researching and planning, then all the time spent in garage over the past couple weekends, was pretty bummed at the failure, right at the finish line. Definitely glad all of the install is in the rear view though!

Thanks guys, really appreciate the help here.

 

[metalheadjoe 10+ year member]

Check restance between + and - battery terminals. Value should be high.

Check resistance between + and - speaker wires. "Resistance" should round to your drivers' load

 

[Trem]

Sorry to bring up an old thread, but have finally had a chance to test everythung with multimeter, with a new amp ready to go.

Checked each speaker at amp connection (ie speed wire), between + and -, and each reads ~4 ohms (front 6x9's are slightly different than rear 6.5). Checked all eight wires against others, and all are 0 ohm. Checked each against ground, 0 ohm.

Have wire brushed the factory ground point, and added some solder to crimped ring terminals on power wire, at fuse, for self assurance of solid connection, but otherwise, have changed nothing. Which doesn't make me confident in connecting and powering the new amp (same Pioneer GM-D9705).

Can anyone punch holes in wiring logic?

4awg power wire to 100A fuse, few inches from battery, to amp. 4awg ground to OEM grounding point (a bolt behind rear seat, where a couple of other wires are grounded to body, and where youtube videos corroborate). PnP connected between OEM deck and truck, with rear channels T'd off of deck to LC2i, then RCA to amp, then all eight channels from amp to PnP, via speed wire. All eight channels of PnP harness snipped between the two connectors, with truck-side spliced to speed wire for connection to speakers. Power and ground wires T'd from deck via PnP harness to LC2i, with remote wire from LC2i to amp. The PnP harness came prewired to LC2i. Let me know if any photos would help.

Really appreciate any feedback on this.

 

[1aespinoza 10+ year member]

and truck, with rear channels T'd off of deck to LC

When you say T'd, do you mean tapped in or completely cut off and spliced in?

 

[audiobaun 5,000+ posts]

When you say T'd, do you mean tapped in or completely cut off and spliced in?

Sounds to me as written in that sentence as though being Taped Off. I could be wrong though. clarification would be appreciated for sure. tied off /Taped of? Which one used? Cut off wiring Still needs to be Capped off or sealed off from being exposed

 

[1aespinoza 10+ year member]

Sounds to me as written in that sentence as though being Taped Off

It would be great if that is the case, that way the solution would be easy peasy.

 

[audiobaun 5,000+ posts]

It would be great if that is the case, that way the solution would be easy peasy.

Right on. I agree man