Big amp shorting out little amp?

[Quillicit]

So I've had my system working perfectly for at least a year, but now all of a sudden the amp that powers my 6x9s is shorting out (no sound, red protection light comes on) when my subs hit at a higher volume. I replaced the amp and the problem persists. I've checked all the wiring and everything seems okay. I disconnected power to the amp driving my subs and the other amp then had no problem pushing the 6x9s at full volume. The subs-amp never cuts out.

Here are the pertinent specs:

Jensen Power 760-4 amp (4 channel, 75w/channel rms) running 2 Kenwood 6x9s

Power Acoustik PS2-1600 (2 channel, 740w rms bridged) running 2 Power Acoustik BM-15W (15" 600w rms, 4 ohm dual voice coil, voice coils wired in parallel, speakers wired in series to amp resulting in 4 ohm load)

I have links to online manuals for all of these if needed. Thanks for any advice anyone can give.

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[brandinooooo 10+ year member]

Voltage drop ?

 

[ahole-ic]

You are having severe voltage problems. You need to do the big 3 and upgrade all grounds.

 

[Quillicit]

What are the big 3? I haven't upgraded my grounds, but I did shorten them considerably today. By the way, nice hat.

 

[brandinooooo 10+ year member]

Big 3 Thread

 

[Quillicit]

Thankya

 

[brandinooooo 10+ year member]

No prob

 

[maylar 10+ year member]

Is it possible that the wiring to the 6x9's is touching something (shorting) with vibration from the subs?

 

[Kangaroux 5,000+ posts]

Check all power and ground connections. My buddy's amp was doing the same thing and it was because one of his power connections was loose and the vibration from the sub would move it around

 

[Spooney 10+ year member]

Is it possible that the wiring to the 6x9's is touching something (shorting) with vibration from the subs?

I'm thinking it is speaker/speaker wiring related too. Do you have other speakers you can hook directly to the amp to test and see if it works like that? It doesn't seem like a voltage issue because it worked fine for a year unless maybe there is a loose ground/power wire or something but his electrical was fine when he first hooked it up.

 

[Quillicit]

Oddly, I did find that the big amp's power was in fact connected underneath the little metal plates rather than between them, so it was secured just by the bottom of the screw (not sure of the actual terminology, but hopefully that paints the picture accurately enough). I fixed it, but this made no difference. I also redid all connections except the grounds at the chassis (which are still very secure and protected from weather so no rusting or anything) and the power at the battery.

Haven't been out to check voltages yet - got the snows on today - but I should be on that tonight or tomorrow. If that reveals nothing, I'll try replacing the big fuse. I'm kind of hesitant to start messing with the big 3 simply because the whole setup was working before and I don't have much experience under the hood.

 

[audiobaun 5,000+ posts]

Could be a bad battery, and the sub amp is drawing all the juice, and throwing the other amp into protect mode from electrical starvation?Ive had this happen before..it was a bad battery.Just something to think about, could even be a bad alternator too??