cant figure out what the problem is.

[stay_high 10+ year member]

I have a Fi Q running off a mb quart onx 1500.1 and a set of ID components on a small amp for the front. The past couple weeks the sub has been acting strange. It started to stop playing every once in awile and gradually started working less and less over the past week. Finally had time to look at it today. I turn on the car and of course it wants to work.. I play it for about 10 minutes at all different volume levels with no problems. then about 15 mins in it cuts out. i go back and check and No loose connections on the amp/speaker wire. The amp was still on when the sub wasnt playing which led me to believe it might be bad RCAS. I tried a different set of RCA's and it still didnt play. I then tried using an RCA to headphone jack and running it straight to my iphone to see if my headunit was having issues. Still not playing. The only thing i noticed upon turning the car on and off is that, the little green power light on the side of the amp will sometimes turn on and sometimes wont. Sometimes it will light up brighter than other times. But the "mb quart" lettering is always lit up. The protect light never turns on so the amp isnt in protect.

and it will work at the random times. Like it wont play for a few days then it might work and sound normal for 5 minutes then just goes out again. Regardless of the volume I play it at. The amp always stays and never goes into protect so its not a bad power/ground/remote connection or anything. The only thing I have left to try is to rewire the sub and see if its the speaker wire that's bad I guess? I could also try a different amp if I can find a friend with one...

I know its kind of hard for anyone to say what could be wrong with it based off this but.. any suggestions?

Click to read more...

 

[stay_high 10+ year member]

So i just hit a speed bump and it caused the sub to turn on and play. Works for 5 seconds then just starts playing a constant bass note and wouldn't stop after turning down HU volume. I had to turn off the HU to get it to stop.

 

[garychurch84 10+ year member]

sounds like the same issue I have.....bad relay in my amp

 

[garychurch84 10+ year member]

Amplifier Issues - Amplifiers / Head Units / Processors / Electrical - SSA Car Audio Forum

 

[Jepalan]

Can you measure the DC voltage across amp's power and ground terminals when it stops playing? I bet you are getting a serious voltage drop.

Check your power lead and fuses from batt to amp. One of the compression screws may be loose, or wire corroded. Also check your ground connection from amp to chassis. Actually remove the screws, shine everything up and reconnect.

 

[negolien]

Can you measure the DC voltage across amp's power and ground terminals when it stops playing? I bet you are getting a serious voltage drop.
Check your power lead and fuses from batt to amp. One of the compression screws may be loose, or wire corroded. Also check your ground connection from amp to chassis. Actually remove the screws, shine everything up and reconnect.

 

[stay_high 10+ year member]

So now whenever i turn on the car its just a constant (and pretty loud) bass note from the sub even with HU on 0. Its the same note that was in the song I had playing when i hit the speed bump and it turned on. It continues until i turn off the HU. I spent the past half hour rewire the sub with new speaker wire hoping for a cheap fix (its at 1 ohm btw) but it did nothing.

I had all this equipment put in a by a pretty reputable shop in tampa florida like 5 months ago.. Also it shoudnt be a voltage drop because the sub is now constantly playing a loud bass note and not cutting out.

 

[trumpet 5,000+ posts]

So now whenever i turn on the car its just a constant (and pretty loud) bass note from the sub even with HU on 0. Its the same note that was in the song I had playing when i hit the speed bump and it turned on. It continues until i turn off the HU. I spent the past half hour rewire the sub with new speaker wire hoping for a cheap fix (its at 1 ohm btw) but it did nothing.
I had all this equipment put in a by a pretty reputable shop in tampa florida like 5 months ago.. Also it shoudnt be a voltage drop because the sub is now constantly playing a loud bass note and not cutting out.

With the system off, unplug the RCA going into the amplifier. If you turn the system back on and there is no sound coming from the amplifier then your problem may lie with the head unit.

A voltage drop measurement is more informative for testing for high resistance in a portion of your amplifier's power circuit than simply watching a voltage meter connected to the battery or your amplifier's power and ground terminals. If you measure more than 0.1 VDC between any two sequential points in the circuit, such as between the amplifier's ground terminal and your chassis ground connection, you have high resistance.

 

[stay_high 10+ year member]

With the system off, unplug the RCA going into the amplifier. If you turn the system back on and there is no sound coming from the amplifier then your problem may lie with the head unit.
A voltage drop measurement is more informative for testing for high resistance in a portion of your amplifier's power circuit than simply watching a voltage meter connected to the battery or your amplifier's power and ground terminals. If you measure more than 0.1 VDC between any two sequential points in the circuit, such as between the amplifier's ground terminal and your chassis ground connection, you have high resistance.

I dont believe it is the head unit. Because i used a rca to headphone cord (whatever they are called) and ran it straight from the amp to my ipod rather than using the head unit and there was no output. This was yesterday before the sub started to constantly play

 

[garychurch84 10+ year member]

tap on the amp

As I stated above I have this problem...faulty relay that I'm having trouble finding a replacement for.The link I posted above as a video in the tread of me verifying this