very strange

[Virtual_Unknown]

for some reason whenever my engine is off and i have my stereo on there is a loud hissing noise coming from the speakers which are running off my amp, whats really weird though is that the hissing stops if i either use the elec windows or if i press the foot brake - anyone got a clue what is causing this?

 

[MikeC]

think you may need a suppressor, but usually thats when the engine is on, it is weird tho

 

[Virtual_Unknown]

suppressor??? what one of them when their at home?
yeah, its only when the engines off, just a really loud hissing that goes after i use the elec windows or pump the footbrake. its not a major issue but just a bit annyoing!

 

[dangermouse_se]

Apologies if you know all this already...

Where have you :

A) Taken the power for the amp?

B) Earthed it?

The power feed should be straight from the battery with proper amp wiring and you need to make sure you have a good earth, I usually use the rear light earth point in the boot. If the amp is at the front there are pleanty under the dash. Dont splice into an earth wire, use a body earth point.

 

[Adams_16v]

i had this with my old alpine stereo, not sure what it was but when i changed it it was fine!

 

[dangermouse_se]

Sounds to me like a bad power feed either the power to the amp or the earth. When the engine is running the extra juice (you get more from the alternator than your battery) is overcoming the problem.