NVX Amp Power Issue

[MikeHolliday]

Put your Red Meter probe on the side going back to the battery and the black probe on the car frame, you should get above 11.5 to 13 volts. That will show that power is getting to the fuse. Now move the Red probe to the Amp side of the fuse. If the fuse is good you should get the same voltage.

 

[smilepak]

 

[smilepak]

Put your Red Meter probe on the side going back to the battery and the black probe on the car frame, you should get above 11.5 to 13 volts. That will show that power is getting to the fuse. Now move the Red probe to the Amp side of the fuse. If the fuse is good you should get the same voltage.

I get 12.1 on both end

I wonder if the amp converter is bad

 

[Doanster1]

View attachment 623612

Yep. That’s the 100A in-line fuse. Either check for impedance or voltage like @MikeHolliday stated above.

 

[MikeHolliday]

Check the Power at the amplifier the same way. Red Probe on the Red Positive 12 volt input of the amplifier and the Black negative probe on the frame of the car.

If you get 12.1 volts, then place the red probe on the Positive Red 12 volt input on the amp and the black probe on the Black negative 12 volt input on the amp. If you get 0 volts then your ground is bad. Follow the negative cable to where it connects to the frame to make sure that it has a good connection.

I sent you a PM with my phone number if you would like to call me...

 

[Doanster1]

I get 12.1 on both end

I wonder if the amp converter is bad

In your earlier post you said there was a fuse internal to the amp that you checked? Check it again if so, but with the meter this time.
Next would be to check the switched 12v at the amp, the line that tells the amp to turn on because you’re actually in the car/listening to music (otherwise it’d be on all the time). With the car on/music playing touch the red probe to the “remote turn on” connector and black to ground. You should get 12v if working or zero if not.

 

[Doanster1]

Another couple easy checks... does the green power LED on the amp illuminate when the car is powered up? If there’s a “protection” LED, is it on/glowing red?
Check the gain knob on the little controller box. Is it accidentally turned all the way down/off?

 

[MikeHolliday]

I am beginning to really believe that the Amplifier is not seeing an Audio signal from the Car. Without an Audio Signal the Amplifier will power up.

I would go back to where I mentioned that when the replace the MCU2 that they did not reconnect that cable. At some location this Amplifier must get an Audio Signal from the car. Without an Audio Signal there is nothing to Amplify.

 

[smilepak]

Ah ok I see where both are you are going. This is helpful. Positive to 12V cable at the amp and negative at the ground cable I get zero. Positive to the remote and negative I get zero.

I tried the red on 12v inline at the amp and black on the car frame against the blue paint I get zero.

 

[smilepak]

I am beginning to really believe that the Amplifier is not seeing an Audio signal from the Car. Without an Audio Signal the Amplifier will power up.

I would go back to where I mentioned that when the replace the MCU2 that they did not reconnect that cable. At some location this Amplifier must get an Audio Signal from the car. Without an Audio Signal there is nothing to Amplify.

That is what I suspect too. Tesla sword everything was reconnected and they took before and after pictures.
I guess I’ll have to take it to the stereo guys to check that for me


Thank you both. This has been a great learning.

 

[Doanster1]

Ah ok I see where both are you are going. This is helpful. Positive to 12V cable at the amp and negative at the ground cable I get zero. Positive to the remote and negative I get zero.

I tried the red on 12v inline at the amp and black on the car frame against the blue paint I get zero.

Last easy check then. The inline fuse at the amp maybe blown. Do the impedance check on it.

 

[smilepak]

Last easy check then. The inline fuse at the amp maybe blown. Do the impedance check on it.

Thanks. I guess another check I can do is check the individual input for power. Could be a bad crossover that prevent signal to the amp to turn it on?

 

[Doanster1]

Thanks. I guess another check I can do is check the individual input for power. Could be a bad crossover that prevent signal to the amp to turn it on?

You already confirmed there is 12v from the battery, but said there is zero at the amp’s power/ground so there’s your smoking gun - the inline fuse at the amp. There is no crossover for power. So check the impedance of the fuse or check the voltage at the battery end of the fuse to ground (not the end that connects to the amp’s power terminal).

 

[smilepak]

You already confirmed there is 12v from the battery, but said there is zero at the amp’s power/ground so there’s your smoking gun - the inline fuse at the amp. There is no crossover for power. So check the impedance of the fuse or check the voltage at the battery end of the fuse to ground (not the end that connects to the amp’s power terminal).

i think there is two fuse inside the amp. Will check that tomorrow.

yes earlier when I place the red on the power outlet on the amp and the black on the car frame, I get zero. Then I tried red on that same power and black on ground, I get zero. Then red on remote and black on ground I get zero.

 

[Cheburashka]

It's possible you aren't grounding the voltmeter correctly. Can you try measuring across ground and 12V that's directly at the amp?

 

[smilepak]

It's possible you aren't grounding the voltmeter correctly. Can you try measuring across ground and 12V that's directly at the amp?

i tried that. Zero. I place the red on 12v line and black on the ground both on the screw on the amp that holds the cable in place.

 

[smilepak]

i think there is two fuse inside the amp. Will check that tomorrow.

yes earlier when I place the red on the power outlet on the amp and the black on the car frame, I get zero. Then I tried red on that same power and black on ground, I get zero. Then red on remote and black on ground I get zero.

 

[Doanster1]

You should def get 12v between the blue power wire and ground. Confirm that that blue wire is the same one at the battery with the high 100A fuse?
As for not getting anything from the remote terminal, if the car wasn’t on you wouldn’t get switched power.

Lastly, pull the two orange fuses on the amp and check for continuity/impedance to ensure they’re not blown. That would explain why you only get .46V at the power terminal though.

 

[smilepak]

I checked the fuse. It’s both beep. I found the cross over or whatever it is called and there is light on there showing signal. I wonder if the ground was not connected on the line in to the amp, the other end of it was not connected might be the issue.

The 12V line is correct one, I traced that back the best I could.

I recall we didn’t use the NVx crossover since it was defective and they gave me this for free. It worked since.

 

[smilepak]

You should def get 12v between the blue power wire and ground. Confirm that that blue wire is the same one at the battery with the high 100A fuse?
As for not getting anything from the remote terminal, if the car wasn’t on you wouldn’t get switched power.

Lastly, pull the two orange fuses on the amp and check for continuity/impedance to ensure they’re not blown. That would explain why you only get .46V at the power terminal though.

Found the issue. Stupid *sugar* didn’t reconnect the ground cable

now I have no idea where this supposed to be connected to hahaha. It’s a short ground cable about 12” in length I think.


View attachment 623911