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Discussion Starter · #1 ·
Hey my name is TJ I’ve had my ST for 10months it’s pretty much close to stock . I’ll get right into it so I had an aftermarket sound system in the car, Two 10” subs a 600watt amp and line output converter. One day on my way to Fredrick MD the subs went out on the highway after reaching my destination I touched the exposed wires that were wrapped with electrical tape spliced into the factory amp wiring harness (I know I should’ve tapped into the factory sub instead) this resulted in no more sound coming from any of the speakers in the car. I assumed I blew my amp the head unit still works and the car acts like it’s playing music but no sound . This issue is the least of my concerns because I plan on buying a new amp however a couple days later of not driving my car one day I went out to start it and it wouldn’t unlock, lock, turn on or start. I went to Ford with the core battery and bought a new one. At first the car was turning on by its own now for the first day or two but after that nothing it has to be jumped in order to start. I’ve tested the battery, starter, and alternator everything is putting out or exceeding expected voltage. Today I took it to advance to get a OBD read even though the car shows NO lights on the dash at all and turns out there’s Lost Communication with the Body Control Module , APIM, and Battery Voltage is below threshold . I plan on checking the fuses again even though I’ve been doing this but if any one has suggestions I’m open to them, thank you!
 

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Depending what the exposed wires were hooked to, you could have a fire hazard/parasitic draw killing your battery. Please undo whatever you did in that area, solder , and install Marine grade heat shrink tubing for your safety.
 

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What exactly did you (tie) into?
 

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Hey my name is TJ I’ve had my ST for 10months it’s pretty much close to stock . I’ll get right into it so I had an aftermarket sound system in the car, Two 10” subs a 600watt amp and line output converter. One day on my way to Fredrick MD the subs went out on the highway after reaching my destination I touched the exposed wires that were wrapped with electrical tape spliced into the factory amp wiring harness (I know I should’ve tapped into the factory sub instead) this resulted in no more sound coming from any of the speakers in the car. I assumed I blew my amp the head unit still works and the car acts like it’s playing music but no sound . This issue is the least of my concerns because I plan on buying a new amp however a couple days later of not driving my car one day I went out to start it and it wouldn’t unlock, lock, turn on or start. I went to Ford with the core battery and bought a new one. At first the car was turning on by its own now for the first day or two but after that nothing it has to be jumped in order to start. I’ve tested the battery, starter, and alternator everything is putting out or exceeding expected voltage. Today I took it to advance to get a OBD read even though the car shows NO lights on the dash at all and turns out there’s Lost Communication with the Body Control Module , APIM, and Battery Voltage is below threshold . I plan on checking the fuses again even though I’ve been doing this but if any one has suggestions I’m open to them, thank you!
I concur with the above. You have a parasitic draw going on somehow. Something isn't shutting off, or worse, you could have a minor or major short somewhere if you melted something.
Start at the battery and confirm there is a draw when everything is off (from the sounds of it this is most likely). Make sure to let the car rest for a while so everything that is supposed to be asleep actually is, then check for current draw. From there, you just have to buckle up and start following it through the entire power bus and fuse blocks. I hate this stuff because I can't read wiring diagrams worth a crap. You could shoot from the hip and maybe save a lot of time and go straight to the amp area and look for it since this is highly suspect already.
The best way I think to do it is to put a current clamp at the battery, then unplug stuff one thing at a time until the current draw stops and you can narrow it down and zero in on the troublemaker. and this can be a PITA on these newer cars because theres all sorts of stuff that stays alive for a while after you shut down, open a door, anything like that. You should hear my wifes Lincoln. I swear that thing is haunted... i go out in the garage at night to grab a coke out of the pop machine and if i get anywhere near that damned thing it starts clicking and clacking and all sorts of stuff. It KNOWS I'm around even if I dont even touch it.. hehe
I'd rather take a hammer to the nuts than troubleshoot an electrical problem.
 

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Discussion Starter · #5 ·
Depending what the exposed wires were hooked to, you could have a fire hazard/parasitic draw killing your battery. Please undo whatever you did in that area, solder , and install Marine grade heat shrink tubing for your safety.
Definitely going to do that thank you
 

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Discussion Starter · #6 ·
I concur with the above. You have a parasitic draw going on somehow. Something isn't shutting off, or worse, you could have a minor or major short somewhere if you melted something.
Start at the battery and confirm there is a draw when everything is off (from the sounds of it this is most likely). Make sure to let the car rest for a while so everything that is supposed to be asleep actually is, then check for current draw. From there, you just have to buckle up and start following it through the entire power bus and fuse blocks. I hate this stuff because I can't read wiring diagrams worth a crap. You could shoot from the hip and maybe save a lot of time and go straight to the amp area and look for it since this is highly suspect already.
The best way I think to do it is to put a current clamp at the battery, then unplug stuff one thing at a time until the current draw stops and you can narrow it down and zero in on the troublemaker. and this can be a PITA on these newer cars because theres all sorts of stuff that stays alive for a while after you shut down, open a door, anything like that. You should hear my wifes Lincoln. I swear that thing is haunted... i go out in the garage at night to grab a coke out of the pop machine and if i get anywhere near that damned thing it starts clicking and clacking and all sorts of stuff. It KNOWS I'm around even if I dont even touch it.. hehe
I'd rather take a hammer to the nuts than troubleshoot an electrical problem.
I agree I believe when I touched the wires it caused a short to the Body control module. I actually study this electrical stuff in school but I don’t know why I can’t seem to find the problem. Is it possible that the amplifier is drawing current from the BCM and or battery? I’m going to try the current clamp at the battery. That’s pretty scary with your wife’s Lincoln lol I’ll update on what’s happened.
 

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Well tell me what wiring you think you shorted out and I can possibly tell you where to look.
 

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Discussion Starter · #8 ·
Well tell me what wiring you think you shorted out and I can possibly tell you where to look.
I wired the RCA turn on wire to the back of the head unit spliced it into the cars antenna wire. Then I also spliced the four line output converter wires to four of the cars factory speaker wires
 

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Do you know exactly which wire you attached your turn on wire to?
I can supply you with wiring diagrams if you need. I'm assuming that yours is an ST3 based on the factory sub statement you made in your first post.
 

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Discussion Starter · #10 ·
Yes I tapped into the yellow/orange antenna wire connected the audio control module. This is the diagram I have
383584
 

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383598


So you tied the remote amplifier turn on wire to the solid state antenna? Correct?

The ACM communicates on the CAN BUS network. If you shorted this or any of the other audio outputs you could potentially damage it.

Try disconnecting the ACM and see if communication resume to normal on the CAN BUS. Don't be surprised to get a U code reporting that the ACM has lost communications with the network.
 
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