Amplifier Issue Post-Install

[JGarver574]

I installed a Polk PA2000.2 2-channel amplifier into my 1990 Sundancer DA. There are two brand new deep cycle batteries already installed. To start the job, I turned the Perko battery disconnect switch off and disconnected grounds from the batteries. I went overkill on the wire (4 AWG) because I may add another amp to the same closet later on and wanted to make sure I could carry enough current to a distribution block.

So, I got it all hooked back up, turned the radio on, tuned and listened for over an hour. It sounds phenomenal. However, kids came back from the beach and it was dark and the cabin lights weren't working. I realized I did not turn the battery disconnect switch back to the ALL position, so I open the bilge back up and turn the battery switch back on which took care of the lights obviously. But then I go to turn the stereo back on to show my wife, and the amp immediately goes into protection mode.

I don't understand what that battery disconnect switch could be doing to throw a brand new amp into protection mode even if there are no There should be ample capacity available on even one of those deep cycles to run

I can provide pictures if necessary.

 

[pyro]

Amp protection mode usually means the outputs to the speakers are drawing too much current and it shuts down to protect itself from blowing up. This is commonly because of a short circuit in the speaker wiring. However it can also occur if the amplifier internally fails.

I would check that it still goes into protection mode with the battery switch off. Perhaps another amplifier is wired into the same speaker loads which was powered on when the battery switch was on - or something wacky like that.

Then I would disconnect all the speaker wires from the amp. Double check input voltage to amplifier is good. If still occurring I would say you have a bad amp.

 

[JGarver574]

Amp protection mode usually means the outputs to the speakers are drawing too much current and it shuts down to protect itself from blowing up. This is commonly because of a short circuit in the speaker wiring. However it can also occur if the amplifier internally fails.

I would check that it still goes into protection mode with the battery switch off. Perhaps another amplifier is wired into the same speaker loads which was powered on when the battery switch was on - or something wacky like that.

Then I would disconnect all the speaker wires from the amp. Double check input voltage to amplifier is good. If still occurring I would say you have a bad amp.

I confirmed before I left that I could shut the Perko battery selector switch back to the OFF position, and the amp would turn back on and play at 3/4 volume absolutely fine.

As soon as I turned the Perko switch back on, Protect Mode.

I used the old speaker wire that was connected directly to the old Sony head unit and just pulled it back to where I mounted the amp, so I know the old speakers weren’t being powered by an amp. The boat is so old though, I’m wondering if there is some sort of pre-amp or EQ or something in-line that I’m not seeing.

I’m going to run fresh speaker wire across the boat to eliminate anything funky going on with that old speaker wire I was using. Other than that, I’m wondering if I maybe nicked a speaker wire and it’s not shorting until I send power down to all the other accessories harnessed in the same channel as my RCA cable and speaker wires.

 

[Wylie_Tunes]

If im reading your past post correctly, the stereo plays with the main battery switch(s) off? Then enters protect mode when the switch is turned on? If so, something is crossed up. Stereo should be powered through the switch, like most everything else. Even wire battery direct, bypassing the switch, turning the switch one should not put an amp in protect mode.

need to measure the voltage at the amp's power cables when in protect mode. If there is proper battery voltage, then with amp off, disconnect positive speaker leads from each channel and power back up. If still in protect mode, power down, pull RCA, then power up. If still in protect mode, its an internal amp issue.

If it goes back to normal mode with the speaker leads disconnected, then reconnect one at a time to see which one is the issue.

If it goes back to normal mode with the RCA disconnected, then this points to the head unit.

 

[Little Ducky]

Grab a volt meter and check to see what voltage it sees when the switch is turned on. Could the amp be seeing 24v?..... vs 12v when the switch is off?

 

[JGarver574]

I'll be back up at the marina today. The one thing I forgot to mention and just realized is that I bought a universal ISO DIN connector from Amazon which has +12V ACC, +12V BATT, and GND pinned, but connected it to a stereo that uses 2-wire power (+12V ACC and GND only, no +12VBATT). The stereo features a super capacitor for on-board memory. It says in the manual NOT to connect +12V BATT to the stereo, which I did.

My concern is that the 2-Wire stereo is going to want to pull way too much current off my switched accessory line, so I will be taking a Bosch relay with me to keep the draw on my accessory line low. I'm hoping this clears it up.

 

[JGarver574]

If im reading your past post correctly, the stereo plays with the main battery switch(s) off? Then enters protect mode when the switch is turned on? If so, something is crossed up. Stereo should be powered through the switch, like most everything else. Even wire battery direct, bypassing the switch, turning the switch one should not put an amp in protect mode.

need to measure the voltage at the amp's power cables when in protect mode. If there is proper battery voltage, then with amp off, disconnect positive speaker leads from each channel and power back up. If still in protect mode, power down, pull RCA, then power up. If still in protect mode, its an internal amp issue.

If it goes back to normal mode with the speaker leads disconnected, then reconnect one at a time to see which one is the issue.

If it goes back to normal mode with the RCA disconnected, then this points to the head unit.

So, figured out a couple things. I had a nick in an RCA cable that was shorting out on the 12V antenna stud. That figured out one problem. After I replaced that, I found out that if I have my water system switch on with my cabin light switch (and 2 or more cabin lights on), the amp shuts down and goes into protection mode. I ran it with zero issues at all if I shut the water system switch off. I am concerned that my alternator needs replaced because underway, the needle on the gauge only reads 12V and bounces around a lot. When idling, it reads 13 steady, which still seems low.

That leads me to another question, how hard is it to install a 3rd deep cycle just for running the sound system. I can find a place for it, but my ProMariner charger is only a 2-battery setup.