After doing all the work on my audio system I ended up hearing a new 'high pitch' electrical noise... at first I freaked and I could only hear it when I started the vehicle... then I realized it was coming from outside... I tracked the noise down to the area of the fuel tank... so chances are it's the fuel pump... is this a common problem? Does it bode ill? Suggestions?

 

if you are hearing that through the speakers you might want to look into installing a GFL isolator or making a completely separate ground set and create a new fuse line for your sound system. removing the high pitch whine from an audio system can be quite cumbersome and sometimes can lead to having to make a separate power supply completely for anything that amplifies audio signals. old wiring can wear out, short circuit, and cause a ground loop fault causing you to hear the alternator and other motors attached to the frame.

as far as the fuel pump goes... to answer your question, you should supply the year, model, and mileage for more help

 

Sorry, should have mentioned it is not through the speakers. It is actually loudest kneeling behind the running vehicle. I've eliminated all speaker noise.. the primary cause was the idiot who installed it ran the power wire under the carpet in the passenger side and used an open-unsealed butt-splice there which when mixed with salt and water did not do very well. I re-wired everything and fixed that issue, the 2nd audio issue was they used the head-unit amp to go into the factory amp, I re-wired it to use the hide-away pre-amp outputs to go into the factory amp and it now sounds as good as you could possibly expect from a factory installation.

This is a 2003, Disco IIa HSE7.

 

Does the fuel pump also whine with a full tank of gas on a cool morning, if so it is on it's way out.
Get back to me and i will explain in more detail.
Mike

 

I'll have to check once I get it back. I wouldn't have called the times I heard it cool... it was over 35C. It really sounds like a bad diode or similar.