Amp Cuts In And Out

Siver

So I had a PA 330 amp powering a 10" Kicker sub installed in my 2000 Impreza Outback. When I begin driving for the first time of the day, my sub won't work at all once I begin driving. When the car is just idling, the sub will work fine, but once I begin driving again, the sub cuts out. After I've been driving for maybe 15 minutes or so and the car has warmed up a bit, my sub will play fine with no issue. Even if I shut the car off, go run a few errands and start my car 20 minutes later or so, my sub will still continue to work with no issue. So yesterday I drove down a long hilly road and did a little troubleshooting. My car had been sitting in the lot for a good 5 hours or so, so when I stated driving, my sub didn't work like usual. On the way down the road, after my car had warmed up a bit, my sub still continued to cut in and out. Then I'd flip my car into neutral and cruise down the hill and the sub would work fine. Once I'd shift back into a gear, the sub would go back to cutting in and out. Then like usual after about 10 minutes of driving, the sub would continue to work without any cutting in and out. Any idea what is going on?

mdaudioguy

Check your ground. Make sure it's secure. Then double-check ALL connections.

AND, welcome to Club Polk!

Siver

If it had something to do with a bad ground connection or wire connection, then why does this only happen before my car has a chance to warm up? Once my car has been running for 10 minutes or so and is warmed up, my amp no longer cuts in and out

treitz3

Metal physically expands and contracts, making or breaking a weak or loose connection. Check all ground wires or install a new one.

Siver

what about my alternator? My alternator gives off a little over 15 volts which is a little high. Would 15 volts be enough to cause the amp to shut off because it is going into protect mode?

F1nut

Metal physically expands and contracts, making or breaking a weak or loose connection. Check all ground wires or install a new one.

Excellent advice.

what about my alternator?

If it outputs 15 volts after you just start the car, it'll output 15 volts 10 hours later. In other words, that ain't it.

Topper

mdaudioguy wrote: »

Check your ground. Make sure it's secure. Then double-check ALL connections.

AND, welcome to Club Polk!

x2 on everything

AudioGenics

1...Try a direct positive + feed connection to the battery.
2...ensure your ground is securely chassis attached removing any paint, rust
3...re-check all connections

Welcome to Club Polk

Siver

If it's not the alternator over powering the amp, then why does my amp work when I'm in neutral rolling down a hill, but start cutting in and out once I shift back into gear?

F1nut

Maybe it prefers a neutral sound rather than a foward one. :biggrin:

Seriously, it's not the alternator.

BeefJerky

Seriously, it's not the alternator.

Unless the alternator's voltage regulator isn't doing its job properly at higher RPM's, which is entirely possible. I've had that happen, which caused all sorts of weird problems. However, note that most modern-day alternators have the voltage regulator embedded inside, so it's not a separately replaceable part. I've also experienced an issue where a bad wire going from the fuse box to the field on the alternator caused unstable voltage output.

It's unlikely that it is outputting excessive voltage, as you would likely be experiencing other issues such as recurring blown bulbs. However, unstable voltage or excessive ripple is not out of the question. If you're concerned about the alternator, it wouldn't hurt to have Auto Zone or someone else test it.

Siver

There's a little red light with the word "Protection" next to it. If my amp was shutting off because it was going into protection mode due to too much voltage, that light would come on right? So would it be safe to say that if that light comes on, it's my alternator, and if it does not, it has to do with a bad connection?

disneyjoe7

Protection light coming on is must likely a short on the output of the amp, and not voltage. I'm thinking you have a speaker wire then it shorting to the frame of the car. Recheck all wires.