Audio Systems: MA Audio 689I, car chassis, amp power

Question
Having an output issue with my M689I amp. Power and Protect lights are cycling on/off constantly. Very little sub output.

Answer
Are you using it in stereo or mono-bridge?  And, what is the impedance of the speaker(s) you have loaded on the amp?

Are you using a power cap?

Have you checked the ground connection to the amp? It must be rock solid and screwed tight to bare metal.

Have you checked the speaker wiring to make sure there is not an accidental short to car chassis?  

Have you checked the speaker(s)?  A shorted voice coil cans cause the problem you are experiencing.

Hope these ideas will help you find the culprit.  My suspicion is either the ground is not a good one or you have a shorted down voice coil in one of the speakers.

Thanks for your question.
C