FosGate 400a4

[Gusel9]

Working on FosGate 400a4. This amp have a problem where
If I connect the remote at ones my ps amp gage goes over
20 amps, But when I top the remote and
The connect it, everything works just fine. ( everythin)

[I Am An Idiot]

What I think you are trying to say is: When you connect the remote wire to the remote terminal, the amp pulls current and pegs your amp meter on your power supply. And if you briefly tap the remote wire to the terminal and then connect it again, all is fine.

Is this what you are trying to say?

[Perry Babin]

If you apply remote voltage initially and hold it there. Will it continue to draw 20+ amps for more than 1-2 seconds?

[Gusel9]

That's exactly right, if I leave the
remote cable on the remote connector
For more then 2 seconds My power
mosfets shorts out, also after it has
Been working fine for minutes, all I
Have to do is disconnet remote from
Remote connector for 4 or more
Seconds, reconnect againg, and problem
repeat it self. Thanks for your help.

[Perry Babin]

If you disconnect all of the speaker wires from the terminal blocks and disconnect the RCA cables, does it act the same?

Would you be able to measure the voltage at several points inside the amp?

[Gusel9]

I will like to mention that I have just add a 2
ohm resistor to the b+, and after applying
remote cable to remote connector, power
supply goes up about 2 amp, then goes all
normal.

[Gusel9]

Yes it does do the same with or without speakers And rca
cables connected. I replece the tl494 and, The pots are all
counterclockwise, but no luck. Can this be relate to a soft
Start, or dtc condition. The 2ohms resister on the b+ does
help alot.
Ones again. thanks for your quick response.

[Perry Babin]

Was it doing this before you replaced the 494?

When you power it up and it's drawing excessive current, measure the DC voltage across the 0.1 ohm source resistors. Do any have more than 0.000v across them when it's drawing excessive current?

With the black probe on pin 7 of the 494 and the red probe alternately on pins 9 and 10, does either remain at or near ground and the other go to ~B+ (whatever that is when it's drawing excessive current)?

[Gusel9]

I replaced the 494 thinking
It was cousing this problem.
now, I only have 1-2 seconds
to do The vol drop test to the
1ohm Resistor. any sugestion?

[Perry Babin]

If you power it up through the 2 ohm resistor and have the transistors clamped to the sink, you can take your time. There won't be enough current flowing through anything to cause any damage. The voltage across the 0.1 ohm resistors will be less than when powered directly but you should be able to read voltage across them if the problem is in the audio section.