jr07 Posted August 3, 2014 Report Share Posted August 3, 2014 Guys, This is mind boggling. I installed a sound system in a 2013 Ford F150 supercrew. Maintained the head unit/bluetooth by tapping into the factory wiring after the factory amplifier. Ran speed wire to an Audio Control LC7i for rca signal to the amps. Channel setup for the processor input is: channel 1) front tweeters signal, channel 2) rear door signals, channel 3) front mid signal. Channels 1 & 3 are internally summed for output to my sub amp signal (front tweeter and mid signal will provide a full signal). The other two outputs are for 4 channel amp. 4 channel amp for front components (100w rms) & back coaxials (60w rms). I've had problems with the system since the install. I haven't actually sent a signal to my sub amp because of what's happened. 1st problem was the initial hookup to my components in the front. Before I hooked them up, I already had the back coaxials on. When I wired up the mids, it sounded really weak and a little distorted. I adjusted Channels 1 & 2 output on the LC7i with no problems. I moved channel 3 output, which is summed signal of front tweeters/front mids, a fraction... and the first amp smoked. Turned it off, moved the channel 3 output back down...the whole fraction i moved it. Plugged everything back up...worked. Eventually with time, I start my car with the headunit off and got a loud high pitch noise along with some smoke in the amp. Amp crapped out a little later. Got another amp..sounded good. All that time, I had issues with my rear passenger coaxial speaker. Eventually, it ended up going out. Pulled the door panel off, and found that the speaker would work when i pushed the cone in a little. Ended up changing the coaxial with the same speaker. Got in touch with a friend. He was tuning the sound system with an oscilloscope. When he went to adjust the channel 3 ouput on the LC7i, that same high pitch "beep" happens, and amp goes into protect mode. Amp actually cooked and the rear coaxials were both locked up. I get there and we start looking at everything. Here are some of the readings for the input/outputs of the LC7i and new Amp: Testing with 1K tone Inputs to LC7i (speaker wire coming out the factory amp) One thing we noticed on the oscilloscope. when the truck turns on, there is a huge spike in voltage (28.7 volts) coming from the signal wires from the factory amplifier. We installed a TR-7 module to delay the signal and remove the ability for the spike to reach the LC7I. Tweeter signal: Left- 3.95volts @ 1k Right-4volts @1k Rear signal: Left-7volts @8.7k Right-7.3 volts @7.4k Front Left-4.7volts @ 8.8k Right-5.26volts @ 14.23k Outputs from LC7 Channel 1: Front Tweeter Left-2.25volts @ 1k Right-(Had a significant increase in voltage-don't know the reading) Channel 2: Rear Door Left-2.8 volts @1K Right-2.8 volts @1K Channel 3: Front Mids Don't remember the readings When tested with 4k tone, All 3 channels looked great; All channels fell between 5.08-5.1 volts @4k. Put a new rockford amp on, 4 channel 486 rms actual The outputs read) Rears 18.8volts, Fronts read 20volts. While having the amp on, no noise....amp just went into protection mode. System cooked the amp. So far, here are all the things we narrowed it down to: front mid input signal, front tweeter signal, something funny going on in the factory amp that i tapped in on the outputs, or the LC7? Anyone have any suggestions?? Link to comment Share on other sites More sharing options...
jr07 Posted August 3, 2014 Author Report Share Posted August 3, 2014 by the way, all polarity was checked for each speaker. Link to comment Share on other sites More sharing options...
OrionStang Posted August 3, 2014 Report Share Posted August 3, 2014 Too much reading for my intoxication level. But I will say, fuck factory amps. Bypass at all cost. SMD Super Seller My Feedback Thread Link to comment Share on other sites More sharing options...
slamingsuburban Posted August 3, 2014 Report Share Posted August 3, 2014 from the sound of it its ether the factory amp thats messing you up or the lc7. can the lc7 be hooked up before the factory amp? Link to comment Share on other sites More sharing options...
jr07 Posted August 3, 2014 Author Report Share Posted August 3, 2014 Right now, I have the LC7 taken out. I ran the rear input signal straight into the punch series (accepts hi-level). No problems at all. So like I said, that's why we were able to narrow it down to being the factory amp under the center console, the front mid signal, or the front tweeter signal coming out of the amp. I'm not sure if I can tap in before the factory amp, but 75% it fixes the problem. Anyone know if I can use a Metra wiring harness for my Ford F150 Sony Stereo/Bluetooth & Navigation? Link to comment Share on other sites More sharing options...
OrionStang Posted August 3, 2014 Report Share Posted August 3, 2014 Check metraonline. SMD Super Seller My Feedback Thread Link to comment Share on other sites More sharing options...
slowfkncar Posted August 3, 2014 Report Share Posted August 3, 2014 28.7 volts is a crazy spike coming from a factory amplifier output. Could you dissconect the output that is spiking to 27v,and see if it still spikes while dissconected? Is this a Sony/sync system? Could you check with the DMM the resistance of the LC7 input that keeps eating the voltage spike from the factory amp and compare it with the other inputs? Could be a bad LC7. Link to comment Share on other sites More sharing options...
jr07 Posted August 5, 2014 Author Report Share Posted August 5, 2014 AudioControl wants me to send the LC7 in to determine if that's cause of the problems...If not, I'm thinking metra harness off the head unit to skip the entire factory amp. Link to comment Share on other sites More sharing options...
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