Infinity Reference 7541a Car Audio Amplifier - Answered Questions & Fixed issues

no. its kinda like a house plug. think of the one on your laptop, on the plug it tells you it needs 240v to power. but it only puts out 12v to power your laptop. the exact same thing is happening with your amp. the amp only needs 7.5 to work but its taking 12.2 to power it. its normal and nothing to worry over

check the cooling fans inside the amp i suspect that they are not working properly and this causing it to overheat which will shut it down via a thermistor to prevent damage

no for one its a 4 channel amp made for highs mids etc.

now saying that, what kind of subs are they svc or dvc what ohm load and rms wattage each sub can hold or just a model number will do.

accessories is usually the first position of your ignition key when you turn key from off. no ignition lights should be lit and cigarette lighter should work. this is acc circuit.you need to connect acc wire of head unit to this circuit. (can pick it up at cigarette lighter ) but if your looking to wire REM wire to acc ---DON"T--- wire it to the blue wire on back of head unit(rem out)or blue with white stripe.

sounds like ur gains are set to high and is going into protect mode

also what ive seen happen before is the speakers (if mounted in metal shelf or door and arnt bolted down correctly can flex under bass notes and flex the speaker that much the termanls short onto the metal and amp hits protect mode
(rare but worth a look if you think u have elimanted most other things Had a dude come to me when i was working in sydney with this problem )

also could be things like clipping protection , overheat protection ,amp drawing to much current from the alternator

do your lights dim when you hit the bass notes ?

get back to me and im sure we could solve this problem

REMOVE THE RCA INPUTS AND DISCONNECT THE SPEAKERS, THEN POWER THE AMPLIFIER UP WITH THIS NO INPUT, NO SPEAKER LOAD CONDITION. IF IT STILL GOES INTO PROTECTION AND YOU HAVE VERIFIED THAT THE POSITIVE AND ESPECIALLY THE GROUND CONNECTIONS, ALONG WITH THE REMOTE CONNECTIONS ARE 100%, THEN THE AMPLIFIER WILL NEED TO BE SERVICED. KEEP IN MIND, THAT DURING THE INITIAL TURN ON OF THE AMPLIFIER, THEY SOMETIMES WILL ILLUMINATE THE PROTECTION LIGHT WHILE STABILIZING THE POWER SUPPLY AND OUTPUTS, BUT AFTER THAT THEY SHOULD SHOW NORMAL POWER UP. IF YOU GET IT TO POWER UP FINE, THEN RECONNECT THE SPEAKERS AND IF STILL OK, THE RECONNECT THE RCA'S. IF IT IS STILL POWERED UP, THEN START TO TURN UP THE MUSIC. IF IT IS STILL POWERED UP AND NO MUSIC, THEN CHECK THAT YOU DEFINITELY HAVE A PROPER SIGNAL COMING FROM THE RADIO. LET ME KNOW IF YOU NEED FURTHER ASSISTANCE.....V

You might check your ground cable for poor connection. If it is attached to the painted chassis of the automobile, the paint needs to be scraped off a little. Or go to a local audio shop or Walmart and buy a cheap capacitor. It is supposed to hold power in itself providing the amp constant power for just this reason.

Hello shaymus_hoos,

No, it isn't supposed to work that way. Although amps are usually wired with the positive directly to the vehicle battery, they aren't supposed to turn on unless power is supplied on the remote wire.

The problem is most likely in either the head unit or one of the amps. And if not corrected, the amps will sooner or later, completely drain the battery.

First see if it works properly with just one amp connected. Remove the remote turn-on from 1 amp at a time and test with the vehicle and head unit off and then on. If the problem is still there with just one amp connected, either the head unit is at fault or the remote wire is picking up 12V somewhere along it's path to the amps. Make sure you have it connected to the right wire on the Kenwood. Every Kenwood I've seen uses blue/white for the remote wire.

If both amps work OK separately, one of the amps is causing the problem. You may be able to correct it by using a relay to electrically separate the turn-on signal for each amp. You'll need a "double-throw, single-throw" type of relay. Here's a link to the Basic Car Audio Electronics web site that details the connections http://www.bcae1.com/. Connect the remote wire coming from the head unit to one side of the relay coil and ground the other side. Bring 12V positive from an "accessory" lead that is hot only when the ignition is in either the "ON" or "ACCESSORY" positions to one side of both sets of relay contacts (it doesn't matter which side). Connect the other sides of the relay contacts, one to each amp turn-on connector.

Hope this helps.

Hello pianopeter, I have the same amp with the same problem but only when the crossover mode switch on the front channel is set to low pass or high pass. Have'nt fixed that yet cause when I got the amp and put power to it the clip and protect lights would flash back and forth. I turned out to have 2 bad output transistors on the right front channel, I replaced them and amp works great now. Then when I was doing final testing I switched the crossover mode switch to lowpass and your problem occured. I do believe the problem is in the removable board which controls the controls the crossover and input to a point. Try moving the crossover mode switch to flat on both front and rear and let me know if amp works fine that way. I'll be working on this problem soon but would like to know if your problem changes if you move the switch to flat. Please leave me a message as soon as you find out cause this will aid in the process of me fixing problem. I am an electronics tech and buy and fix broken amps all the time so I have a really good knowledge of car amp repair. Once again let me know ASAP, Thanks Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/mark_b53a7494531bf96d

I have an Infinity amp as well, and I was having the same issue for a time. The amp is protecting itself from some sort of overload. It could be the Ohms load on the sub, but I would guess not. Make sure your low pass filter is set to LP and not HP or Flat. Then check the RMS on your subs and match that to the Amp RMS. Once I did all that I found that everything worked fine, for a time. It started doing this again, and I checked the fuse and it was blown badly. It seems that the fuse setup on some of these Infinity amps is not as good as one would hope, because the charge was bridging the gap and frying out my fuses. It was like a spark would jump from one side of the fuse to the other without travelling the fuse itself, and this was causing my protect issues. I pulled the fuse, got a new one of the same rating, but I placed the fuse in with a little piece of rubber in between the 2 contacts, and then connected to the fuse block. I have not had problems since.

Overload maybe. If the amp is run at an improper impedence, the amp will shut down. If you are "CLIPPING" speakers / subwoofers the light will blink to indicate a hard clip . Example: 4ohm/2ohm stable amp with 4 ohm subs wired at 1 ohm.

check the speaker terminals for dc, it should be very low,about 100 mV or less, it it is higher you need to find the pots that adjust dc offset to get it down.Also you can compare voltages with the opposite channel to find abnormalities.

trying to draw to much power off the amp, i would say it isnt big enough for the subs you have or the wire (power) for the amp is way to small. car audio has specific requirements exact specs on all of it will make a big difference in the help we can give.

disconnect all power cables.make a short between terminals G&P G&R then try amp without any speakers connected.

Get it repaired by a car audio shop, if its expensive get a new amp.

hi. your amp has an internal power supply fault. problem lies in the remote turn on regulator circuit or with the pulse width modulating circuit.this fault definitely needs to be in technicians hands. cheers

Does it do the same thing if you remove the RCA input and disconnect the wires from the speaker terminals of the amp?

You would do best with a 12volt inverter. It will bring the house voltage down to the necessary 12 volts for your car stereo. Best of Luck.

this is not an easy diagnostic ,companies hide these amps in special places,amp needs to be check faulty fuse,ground or connections

Try first to disconnect all of the speakers on the amp. See if the amp will turn on now. If not , the amp has bad output devices, or drivers, and or the switch mode power supply is fried. There is no easy fix with solid state elctronics as there are no user serviceable parts inside. The units going to need to be repaired by a service tech unless you know how to solder, unsolder, test mosfets, transistors, and diodes as well as resistor.