Weird problem help requested!!!

[LWW 10+ year member]

I have a 1999 Mazda Miata with a Memphis ST3004 amp mounted in the trunk, an Eclipse CD3432 HU and CDT 6.5" classic components in the doors.

My problem is that all of a sudden the HU has taken to cutting out the sound, although all functions remain intact and lit up, from time to time when a hard road bump or bass note is hit.

The problem occurs whether it is set to CD or radio and has happened completely stopped as well.

All wiring connections at the HU and amp and battery seem fine and the ground is intact and solid. The amp is powering the speakers and bass shakers while all the HU has to do is send signal.

All equipment is less than 6 mths old and has performed flawlessly until this week.

Any and all comments on what is wrong here are appreciated in advance.

PEACE

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[bigred78797 10+ year member]

Well it may not be your HU it may be your amp. With the amp being in the trunk presents you with a slight problem... you cant tell if it is going in protect mode when the sound goes out so you cant rule out the amp... entirely. I know it's alot of work but i would pull out the signal cables and give them a full inspection.. there may be a short somewhere on them. There may also be a semi-short in your speaker wires which would cause the amp to go into protect mode when hitting a bump or when a vibration occured. Also With it being the summer and all your amp may be going into thermal protect mode. Good luck on finding the problem.

 

[LWW 10+ year member]

All speakers run from the amp and if 1 speaker wire were shorting out wouldn't the other still work?

Also the amp is not getting particularly warm. When the sound cuts it does come back within a few seconds to as much as a minute.

PEACE

 

[bigred78797 10+ year member]

When most amps go into protect mode it bypasses ALL the speakers and just about completely shuts down by sending power only through the protection circuit. Thermal shutdown can last for as long or as short as it takes for it to cool down. Or if it's a short then it will remain in protect mode until the short is gone... or until your amp messes up. Have you been able to check the amp while it's not working to see how warm it is? It would also be wise to check to see if ANY of your speakers voice coils are fried. Yes you can have a semi-fired voice coil and not be able to tell by listening. To check to see if it's fried either take it to a shop or use a digital multimeter and check the ohm readings for it.