Help! My amp keeps cutting out (Alpine PDX F4)

[JamieP]

The strangest thing has started happening with my amp over the last couple of weeks. All of a sudden the speakers will start to get a crackle that sounds like radio static (all 4 speakers similtaniously) and then the amp will completely shut off, light and all for about a second and then it comes straight back on. Sometimes it will only do this once, other times it will continue doing it every minute or so to the point where I have to turn it off for a while and give it a break.

What is even stranger is it only does this on long drives. If Im just driving around town it works fine. no problems what so ever. but when I drive from geelong to melbourne, by the time Ive almost reached the city, thats when this problem seems to start happening.

My first thought was that maybe I had a loose speaker connection but its not that. Then I thought maybe it wasnt earthed propperly but its not that either. Have any of you guys who own one of these amps had the same problem? I googled it and another PDX guy posted the same question on a forum but didnt get any replies.

thanks heaps.

[NA15BS]

give us more details on your set up like what speakers are you using, are you running the amp with the subwoofer?

[fitme]

What is even stranger is it only does this on long drives. If Im just driving around town it works fine. no problems what so ever. but when I drive from geelong to melbourne, by the time Ive almost reached the city, thats when this problem seems to start happening.

where did you mount your amp?..is it properly ventilated?

[GaDgeT-CRX]

does your amp go into 'protect' (led light on amp) when this prob occurs??

[JamieP]

Sorry for the lCk of details guys. So I'm running 4 focal Cvx speakers off this amp which is mounted under my passenger seat. No red light comes on when this problem happens, i just here a clicking noise and it shuts off them comes straight back on.

My sub is powered off a separate amp in the boot and it continues playing strong when the other amp shuts down

[2MPRS]

check your ignition wire if it cuts in and out.

[arverson]

sounds like its either:
1) goin into protection mode. if an amp was struggling to cool itself down -especially over a long time(drive)- then itll shutdown. how are the amps setup? hows their ventilation?
2) voltage drop/ground issue. re-check your grounds with a multimeter. relocate if you have to.
3. remote/ignition wire shorting out somewhere. re-check the connections and examine the entire length of wire to ensure no shorts.

but to me it sounds like poor air ventilation.

[NA15BS]

if happens only on a long drive maybe your amp doesnt have enough ventilation mounting it under the seat, try mounting it in the boot if you still have some space... hopes this help,,

[JamieP]

thanks for the help guys. Im thinking it could be a vetilation problem as well =/

[mikul]

have you checked your fuse box ?? ..aka the resistor(s) near your battery ? ...the wires which run through ur fuse box maybe loose. the same thing happen to me a few months ago...it took me a while to figure it out that it was actually coming from the fuse box and not the actual amp. the amp turns on/off like that to protect itself ..u learn something new everyday i guess :)