Amp keeps shutting off

[JSMCO]

Hi guys, having a nagging issue and hope someone can help diagnose.

2002 Jeep grand Cherokee.

Head Unit-Pioneer 1306300UB

AMP-Alpine PDX-5-Gain set right in the middle on both channels and HPF also set in the middle at about 110 hz. Sub Gain slightly past middle and LPF at about 75hz

Fronts-Eclipse SC6500 Components-4ohm-channel 1/2 on the amp

Rears-Kicker 40CS654 2 ways-channel 3/4 on the amp

1 Sub-Rockford Punch P2D4-sub channel on the amp

Amp mounted vertically on the back of the driver's side back seat

The issue is that at higher volumes, the amp stops working (light on the amp turns solid red) and won't come back on unless the vehicle is turned off and then turned back on. By higher levels I mean the max volume on the head unit is "62" and this occurs at about 46-54 depending on gain level at the amp. It works fine and steady but as I slowly turn the volume up when it hits about 46 the amp just goes into protect-no static or squealing or anything, it just flat stops putting out sound. This happens no matter what the temperature, or whether or not the sytem has been on and playing for a while. It does not seem like a heat/temperature issue to me. Here's what I have checked:

Digital Multimeter shows battery voltage steady at about 13.8 volts.

1. I unplug the "blocks" on the amp that output to the eclispes-first the left channel, then the right, and with one or the other unplugged, the amp cuts off when volume gets to about 45-46.

2. If I unplug BOTH blocks going to the eclipses, then I can max out the volume on the head unit and the amp has no issues, the kickers and the sub are fine.

3. If I unplug the kickers and the sub and just run the eclipses, amp cuts off at about 45-46.

4. If I plug the eclipses into channel 3/4 same thing-the amp cuts off at about 45-46.

5. If I reduce the gain on the amp going to the eclipses, I can get the volume up to about 55 before the amp locks, but reducing the gain to the eclipses sends the soundstage to the back seat which is not ideal.

6. The sound is nice and clean...there is no distortion occurring when the amp cuts out.

If this happened with only one or the other of the eclipses, I'd suspect a bad wire or voice coil or a short somewhere...but since either one or both of them cause the issue, and the issue only goes away when they are both unplugged, I'm not sure what to think. Do those speakers or the crossovers have some type of overload protection built in that would cause the amp to lock up like that? The eclipses are rated for 75w cont. which is what the amp puts out going into 4 Ohms so I wouldn't THINK the speakers are being driven too hard but maybe I'm wrong. What steps can I take to isolate the problem? I am in no way an expert but I can get the speakers in and out of the doors, etc if needed. Thanks in advance for any help.

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[michaellane 5,000+ posts]

Low voltage, too low of a ohm load on a channel.

 

[JSMCO]

Thanks for the response Michael-How would I go about correcting either issue?

Is the 13.8 Volts too low?

Is there a way to increase the ohms on that channel using the existing speakers?

Sorry if my questions are dumb..

 

[huberoy123 10+ year member]

Have you tried leaving only one of the eclipse plugged in? If the amp doesn't shut down, plug in the other speaker to see what happens. This should help you isolate which speaker is causing the problem.

 

[shizzzon 10+ year member]

Unhook both eclipses and measure continuity on each of them for about 10-15 seconds per speaker and see if the values measured are staying consistent.

 

[shizzzon 10+ year member]

Also, if they stay consistent, measure again and while measuring, start beating or hitting the inside of the door fairly hard to see if you get any odd readings.

 

[Slo_Ride 5,000+ posts]

There's a short somewhere. Even if it's inside the amp.

 

[JSMCO]

Huberoy-Thanks for the input, the amp cuts out if EITHER eclipse is hooked up to ANY channel on the amp, so yes I have indeed tried unhooking them one at a time.

Shizzzon-Thanks as well-I tested both mids with a multimeter while out of the vehicle-both hold at about 3.5 ohms. Sorry again for possibly dumb question but I admit I am very uneducated at how to test electrical issues: How do I test properly while the speakers are inside the doors? Would I disconnect the speaker wires from the amp and attach the multimeter to the speaker wires at that spot? Or would it be better to try the wires past the crossovers? And since these are a component system should I also test the tweeters for proper resistance? One other thing I tried was disconnecting both tweeters and just running the mids. Same result-amp cuts out at same level as when the tweets were connected, maybe even a little earlier in fact.

Slo_Ride-Thank You as well-If the amp has a short would it not cut off when the kicker speakers are being cranked up as well? It also seems unlikely by my experiments that there is a a speaker wire short. (Unless somehow there is a short in BOTH sets of wires leading to the eclipses which would be pretty big bummer of a coincidence) Is there a way a layman like me could: 1. Test the amp to verify if it has a short? 2. Test the speaker wires to see if there is a short somewhere? (Honestly, I don't even know what type of tool or tester would be correct to test either of these possibilities but I'm certainly willing to listen and learn.

I'm starting to wonder if maybe the amp just doesn't "get along with" the eclipses for some reason or another.

One other thing I have also tried was relocating the amp ground wire to a different location but that did not result in any difference in outcome, either.

Thanks again in advance