amplifier switching off- need help!

[exactly...doh]

hey guys,

just tonight, my amp has begun to switch itself off (protection mode) when i crank the volume. now, this is not a new setup, its been working fine for over two years. i'm only running a sub off it. the problem goes like this:


when i turn the car/accessories on at low volume, the amp light will be green.
if i leave the volume low, it will stay on.
as soon as i try turning it up and getting some bass going, it cuts out and goes into protection mode (red light).
the only way to get the light green again is to turn the whole car off and on again.

ALSO, the stereo will play loud volume, but as soon as any bass comes in, the amp cuts out.
only other thing of note is that for a week or so, the amp has been making a high pitched sound.

the set up (bits you probably need to know) is:
pioneer head unit running a US Audio 4x50W amp (amp is about 5-6 yrs old) and the amp is running a pioneer 12" sub (also 5-6 yrs old)

i've checked:
amp earth, power (and power fuse), remote wire, amp fuse (40A) and rca connection.
i haven't checked any HU connections as yet, but they haven't been touched.


i think the amp has had it.

[rob_o]

www.caraudioaustralia.com

They might help you out there.

[sikmon]

change the big chunky fuse on the power wire... if that doesnt work then ya amps fucked

[exactly...doh]

ok. i don't know what made it work again, but it is.

what i did just before it started working was;

moved the rca's in the amp from channel 1 & 2 to channel 3 & 4.
did the same for the sub wires (bridged on 3 & 4).
fiddled with the fader control on the HU.
and the sub started working.
SO THEN, i put everything back to what it was before AND IT WORKED AS NORMAL.

WEIRD!

[hainerob]

Hows your battery goin?... if its a little on the down side it can cause some amps to hit their minimum voltage setting and cut out.

Before you replace anything...
Set your amp up on the floor of your lounge room and see if it still happens. grab a jump pack or somethin to try it out.

[DEVILsEXA]

Was most likely just a speaker wire touching (wires from amp to sub) or the rca wasn't quite in properly.

[ZeffriN]

yeh what Devils said