Car audio - what would cause an amp to cut out?

[Smoove910]

What does your ground connection look like? I keep wanting to think it's a grounding issue with your amp.

The red LED on the amp is telling you one of these issues:

Protect LED
• Illuminated under any of the following fault conditions:
battery over/under voltage, short circuit in speaker wires,
amplifier is too hot, amplifier's output circuit has failed (DC
voltage present in the amplifier's output)

Lastly, it also seems as though your mids/tweets are primarily affected for whatever reasons. Is there a chance they have been exposed to moisture in your doors? Corrosion on the connections? Just trying to think outside the box so to speak.

 

[SuperSix]

That won't make a damn bit of difference. In fact, the amp would run cooler and easier since there would be less load...


To OP - You need to run the RCA's away from your power/ground. That's probably why you are getting engine noise... There should also be no reason for RCA's or speaker wire in your engine compartment. Did you happen to install car stereos for Best Buy at one time cause this is starting to look like the type of work they do.

Yes it will. It doubles the load on the amp, making it work harder. Effectively cutting the output power in half.

 

[jlee]

Doubtful on moisture in the doors, since this has been an issue ever since this setup was installed. I ran new wire, too - didn't re-use existing speaker wire. I think it's narrowed down now, but since I already took photos:

I tried grounding to the empty bolt here, and sanded the paint clean below the washer.

Sound coming out of both sets of speakers with a single input is normal when it's bridged. You're bridging across the left and right channels, so the output is the SUM of L+R. (Which is why I wouldn't recommend bridging. It turns the stereo effect into a half-volume effect.)

Now, if what you've said is the totality of what you've tested, you haven't yet tested your L+R components separately. (You've tested them together in bridged with a mono input, and together in Front with a stereo input.)
For testing them individually, remove the speaker leads, not the input RCA. This is necessary because Left and Right aren't electrically isolated in the amp. (L- is actually the same as R+.) So if you have a path to ground in one side you'll pull the other side down as well.

Unplug your front right component and leave the left one in. Don't run it bridged, try it in each of the amps four channels and see if it cuts out. If it never does, try the same thing with the right component and the left unplugged. If it doesn't cut out, try the two unbridged on the front and then again on the rear and see if it cuts out together.

Beautiful..thanks guys! If I disconnect the passenger side from the amp, it'll work fine (left the subwoofer on). If I reconnect the passenger side and disconnect the driver side, it'll cut out.

Soo...passenger door is getting pulled apart and I will test the speaker outside of the door, with all wiring in plain view - if it works, I screwed up that speaker wire - if it doesn't, the speaker is bad?

 

[Smoove910]

Yes it will. It doubles the load on the amp, making it work harder. Effectively cutting the output power in half.

So you are saying an 8 ohm sub will work the amp harder than the 4 ohm sub? Please show proof of your claim if it is.

I've even opened you a google search:

http://www.google.com/search?aq=0&o...q=difference+between+4+ohm+and+8+ohm+speakers



OP - It sure looks like you are almost there! Show some more pics if you find anything...

 

[jlee]

So you are saying an 8 ohm sub will work the amp harder than the 4 ohm sub? Please show proof of your claim if it is.

I've even opened you a google search:

http://www.google.com/search?aq=0&o...q=difference+between+4+ohm+and+8+ohm+speakers



OP - It sure looks like you are almost there! Show some more pics if you find anything...

Definitely - I may try to pull the door panel off tomorrow and see if I find anything obvious. Unfortunately Sunday is tied up working on another MR2, but if I don't get to it by then Monday afternoon should be available.

 

[EightySix Four]

Beautiful..thanks guys! If I disconnect the passenger side from the amp, it'll work fine (left the subwoofer on). If I reconnect the passenger side and disconnect the driver side, it'll cut out.

Soo...passenger door is getting pulled apart and I will test the speaker outside of the door, with all wiring in plain view - if it works, I screwed up that speaker wire - if it doesn't, the speaker is bad?

Yeah, if it continues to cut out after it's taken out with a short run of speaker wire, the speaker is bad and you can RMA it. It may be smart to test with/without the cross over if it has problems as well.

 

[sdifox]

Doubtful on moisture in the doors, since this has been an issue ever since this setup was installed. I ran new wire, too - didn't re-use existing speaker wire. I think it's narrowed down now, but since I already took photos:





Beautiful..thanks guys! If I disconnect the passenger side from the amp, it'll work fine (left the subwoofer on). If I reconnect the passenger side and disconnect the driver side, it'll cut out.

Soo...passenger door is getting pulled apart and I will test the speaker outside of the door, with all wiring in plain view - if it works, I screwed up that speaker wire - if it doesn't, the speaker is bad?

another thing you should try is to wire the driver side speakers to the right channel (do the same with source). This way you test the amp to make sure it is fine.

 

[DominionSeraph]

Yes it will. It doubles the load on the amp, making it work harder. Effectively cutting the output power in half.

LOL no, that's not how electricity works.
Infinite ohms is no load. Zero ohms (a short) is max load.

Electricity follows the laws of physics. It doesn't try to go "above and beyond."
The amp isn't failing to reach its goal when outputting across 8 ohms -- it's outputting exactly what it's supposed to: Half as much. So it has ~half the current passing through it, meaning ~half the waste heat generated by its internal resistance. And you won't run into any power clipping issues because its power circuitry is designed to maintain voltage across twice the load it's seeing. (You could still drive the amps out of linearity but it won't have a problem powering that non-linear signal)

 

[DominionSeraph]

Soo...passenger door is getting pulled apart and I will test the speaker outside of the door, with all wiring in plain view - if it works, I screwed up that speaker wire - if it doesn't, the speaker is bad?

Pretty much. If there's no path to chassis ground (speaker wire) then it looks like you have an internal short, which could be in one of the component speakers or the crossover.

 

[exdeath]

Mm melted voice coils smell like hot bandaids :awe:

I see your problem, the leader of the Decepticons is powering your electrical system.

 

[exdeath]

Yes it will. It doubles the load on the amp, making it work harder. Effectively cutting the output power in half.

Its the other way around. Running a 2 or 4 ohm high current low impedance driver on a weak 8 ohm amp will burn up the amp if its not designed to sink that kind of current.

 

[jlee]

Mm melted voice coils smell like hot bandaids :awe:

I see your problem, the leader of the Decepticons is powering your electrical system.

D:

I think I'll try swapping crossovers first...if that doesn't work, I'll pull the door apart. If that does work, I'll RMA the crossover.

 

[jlee]

Update.

If I connect the passenger side component to the other (left) front output, it's fine. If I connect both components to the rear outputs, it's fine (at max gain, almost max volume).

Problem solved - faulty front right on the amp?

 

[Smoove910]

I suppose you could try to reconnect the passenger side back to the right front of the amp and then swap the right and left front input RCA's. This will ensure it is indeed the amp and not the RCA connection too.

 

[sdifox]

Update.

If I connect the passenger side component to the other (left) front output, it's fine. If I connect both components to the rear outputs, it's fine (at max gain, almost max volume).

Problem solved - faulty front right on the amp?

sounds like bad amp.

 

[alevasseur14]

Update.

Problem solved

:thumbsup::thumbsup::thumbsup:

 

[sdifox]

So any update on this?

 

[SAWYER]

I had an amp doing this and it was a bad ground

 

[jlee]

It's been running fine on the rear channels..going to RMA it.

 

[sdifox]

It's been running fine on the rear channels..going to RMA it.

ok.

 

[BlahBlahYouToo]

loose ground.

 

[jlee]

the ground is fine, guys....read the last few posts.

 

[sdifox]

the ground is fine, guys....read the last few posts.

You are grounded!

 

[GameFace24-7]

So I'm having similar issue with my Kicker Marine Amp install on my golf cart. When I turn it up past 20 the amp cuts out and the blue LED light off. If I turn the gain all the way down I can get more volume but obviously no bass from the Sub. Just to be clear I'm following, after testing everything you RMA (returned merchandise) it because it's had a faulty front right on the amp?

I have everything wired so I'm going to go through all the outputs to see if I can get near max on the volume and gain and see if I can isolate the bad output, but it sounds exactly like what happened to you JLee.

Problem solved, moving on, thread locked. Please feel free to start your own thread detailing your issue, it may generate more traffic and help you with a solution to your problem.

And welcome BTW.

~DaTT

 

[jlee]

Whoa, blast from the past!

If I recall correctly, my RMA'd amp had the same problem. I replaced the speakers and everything was fine.