Random thumps and diagnostic light

[OMGASAXO]

My sub is making random boom noises and the diagnostic light has lit up red on the amp? What does this mean? I've checked all wires are correctly fastend. I have the earth a good clean and secured it back down.. But it's still thudding. Had to disconnect it from the battery for now.

[stevo67]

Internal fault with the sub,hate to sound obvious mate.

[OMGASAXO]

With the amp? Tried a different sub and same happens

[Ben_SaxoForte]

Have you got the user manual to the amp? Maybe it will tell you the reason why the light could be on.

Also this could be worth a try

Description of the PROTECT system built into amplifiers........
The diagnostic system will shut down the amplifier, until reset by turning the head unit off, and back on. This state of affairs will be indicated by the front panel PROTECT LED lighting up under the following conditions:
1 - A short circuit on the loudspeaker leads.
2 - An internal amplifier fault that causes a DC offset on the loudspeaker output.

Should the amplifier go into protect mode, simply disconnect all RCA and speaker leads, while keeping +12 volt, power ground and remote leads connected.
1. Now turn the amplifier back on, and if the diagnostic LED lights, the amplifier has an internal fault.
2. If not, plug the RCA cables back, and reset the amplifier. If it goes into diagnostic now, the fault lies in the input, either with bad cables or source unit.
3. If the amplifier seems fine with RCA cables plugged in, connect the speakers, one at a time, and if one of the speakers or its wiring is faulty, it will activate the diagnostic
system.

[stevo67]

Originally Posted by OMGASAXO

With the amp? Tried a different sub and same happens

Then you have a wiring fault mate.