no output from amp
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=128401
Printed Date: May 03, 2024 at 3:22 PM
Topic: no output from amp
Posted By: pv13
Subject: no output from amp
Date Posted: August 30, 2011 at 8:37 PM
I installed a kicker 1200.1 amplifier and a kicker 12 inch L7 in my cousin's 1996 BMW M3 the other day. Everything powered up, but there was no output from the subwoofer.
I got 12 volts on the power and remote wires,and 0.5 ohms on the ground wire. I took out the speaker wire from the amp and checked the ohms, and it had a proper 2 ohm load.
I ran a new set of rca cables outside the car from his pioneer avh-p6500dvd head unit to the amp, and still no sound.
What could it be? Is the amp bad? Is the headunit bad? Is there anything else I can test?
Replies:
Posted By: soundnsecurity
Date Posted: August 30, 2011 at 9:15 PM
unless you have a spare amp to temporarily swap into the system to test, then it will be hard to test. make sure you have the rcas plugged into the right outputs. you could also try to put a line output converter on the speaker wires and plug the rca into that just to see what happens, if you still get no sound after that then i would suspect your amp is no good. if you do get sound then you have a blown output on the pioneer.
you also might need a better ground, 0.5 ohms is kinda high for a ground.
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Posted By: i am an idiot
Date Posted: August 30, 2011 at 9:37 PM
Make sure you did not wire one of the voice coils out of phase.
Posted By: pv13
Date Posted: August 30, 2011 at 9:42 PM
i am an idiot wrote:
Make sure you did not wire one of the voice coils out of phase.
If I did, would the DMM still read 2 ohms? Also would I get any sound from the sub? Because I did put a 9 volt battery to the speaker wires to pop the sub to make sure there was a connection.
Posted By: i am an idiot
Date Posted: August 30, 2011 at 10:12 PM
Yes it will read 2 ohms even if one coil is out of phase. You need to pop both coils at the same time, if the speaker moves, then one coil is not out of phase, if it makes a small pop but does not move, then one coil is out of phase.
Posted By: pv13
Date Posted: August 30, 2011 at 10:25 PM
Alright, I'll check it out tomorrow and get back to you. Thanks
Posted By: pv13
Date Posted: August 31, 2011 at 1:16 PM
Everything is wired properly. The amp powers on, but still no output. And i checked my ground again, and it reads 00.2 ohms. Is there anything I can try, short of putting in another amp to test it?
Posted By: pv13
Date Posted: August 31, 2011 at 1:19 PM
soundnsecurity wrote:
unless you have a spare amp to temporarily swap into the system to test, then it will be hard to test. make sure you have the rcas plugged into the right outputs. you could also try to put a line output converter on the speaker wires and plug the rca into that just to see what happens, if you still get no sound after that then i would suspect your amp is no good. if you do get sound then you have a blown output on the pioneer.
you also might need a better ground, 0.5 ohms is kinda high for a ground.
Where would I put the line output converter?
Posted By: casofwaco
Date Posted: August 31, 2011 at 1:27 PM
most LOC that ive worked with just tag into the rear speaker outputs. since u already have rca's ran u can install it behind the radio. Have u checked that the sub output was turned on in the head unit. i sometimes have brain farts and forget to turn it on when doing an install.
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Posted By: pv13
Date Posted: August 31, 2011 at 2:02 PM
casofwaco wrote:
most LOC that ive worked with just tag into the rear speaker outputs. since u already have rca's ran u can install it behind the radio. Have u checked that the sub output was turned on in the head unit. i sometimes have brain farts and forget to turn it on when doing an install.
Okay.And yeah, the stereo settings are kind of confusing, but I did make sure the subwoofer setting was switched on. I'm trying to talk him into getting a more modern deck like a new alpine, as I feel this pioneer has run its course.
Posted By: i am an idiot
Date Posted: August 31, 2011 at 4:56 PM
Set your meter to AC volts, unplug the RCA connector from the amp, place the meter leads on the RCA cable, turn the volume up, does the meter reading change with the volume of the music?
One meter lead on the center conductor, the other meter lead on the Shield connection of the cable.
Posted By: pv13
Date Posted: August 31, 2011 at 7:14 PM
i am an idiot wrote:
Set your meter to AC volts, unplug the RCA connector from the amp, place the meter leads on the RCA cable, turn the volume up, does the meter reading change with the volume of the music?
One meter lead on the center conductor, the other meter lead on the Shield connection of the cable.
Did the test with the RCAs, and yes the meter reading changed. Does this mean that the problem isn't with the rcas or the headunit?
Posted By: i am an idiot
Date Posted: August 31, 2011 at 8:50 PM
That does point to that direction. If you turn the volume all the way down and the meter reads 0.000, then it begins to raise as you turn the volume up (In accordance to the music playing as well) This would lead me to believe that the problem is with the amp, it's switches, or the wiring. Have you verified that you are getting 12 volts across the power and ground terminals of the amp?
Posted By: pv13
Date Posted: August 31, 2011 at 11:22 PM
Yeah, I've triple checked the wiring. Its all brand new, and I'm getting 12v all across. I got my hands on another amp to see if I get any sound from the sub. Hopefully, I can take a look at it tomorrow. Thanks
Posted By: pv13
Date Posted: September 01, 2011 at 8:15 PM
Put in another amp to test the sub, and it works perfectly. It would have saved me alot of troubleshooting if I just could have gotten an amp in the first place. Thanks for the help.
So I guess I need to get another amp or have this one fixed. Is it even worth fixing?
Posted By: i am an idiot
Date Posted: September 01, 2011 at 8:50 PM
Is there a protection light on the amp? Is it lit?
Posted By: pv13
Date Posted: September 02, 2011 at 1:04 AM
There is a protection light, but it isn't lit.
Posted By: i am an idiot
Date Posted: September 02, 2011 at 10:59 AM
It may be a simple repair, and then again it may cost you 100 to 150 dollars to get it repaired. When it powers up, do you hear the relay energize? You may have to put your ear ON the cover to hear it. I am pretty sure the relay on that amp is located very near the speaker terminals.
Posted By: pv13
Date Posted: September 02, 2011 at 3:12 PM
I hear something, but I don't know enough about the internal aspects of an amplifier. My cousin apparently knows a guy who can take a look at the amp and possibly fix it, so I guess I will have to go from there.
Thanks for all your help.
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