Hi Duncan,

I have the same issue. Occasionally the speakers sound like they're hooked up to a dentist drill. turning the headunit off does not fix the problem. The last thing that fixed it was turning my aftermarket Alpine amp upside down (it was just loose in the boot), which leads me to think that it's either the Amp or it's the wiring to the amp - either way the problem went away.

So do you have an aftermarket Amp fitted?

Ade.

 

it was still there when you disconnected the amps ???
i dont see how if all your drivers are amp-powered .

check the connections on the back of each speaker , water may have got in the door and made you a bad earth .

take off the fuse box lid in the engine compartment , the supressor is clipped to the back of the mounting plate , out of sight . but you can see the 2 thick wires coming to the front and connecting by a plu , un-plug it and "borrow" one from a freind temporarily to see if that cures it !!!

most car stereo noise comes from the alternator , basically as that is the main part of the electric system !!! this is where the factory noise supressor connects to

could also be a bad output stage on one of the amps .
or a bad earth from the amp chassis . are they securely fastened through the chassis , or have a wired earth to the chassis ?

temporarily connect a wire from amp chassis to car chassis/battery earth , see what happens . also check the rca leads etc. as everything in the stereo system should have an earth

 

Duncan,
Do you have an oscilliscope? If the whine is increasing with RPM than there is a really good chance you have a failing diode pack (or regulator or something) on your alternator. Your local auto parts store might rent alternator tester for free (I think mine does).

 

Rennlist Mindmeld across the Pacific?

 

I removed the alt. last night and the noise stopped. Has the source been located?

Jason, should I overhaul the alt? It's probably about time, I already have it out, and it is 13yrs old.

Tafkai, the amps had already been removed and a speaker was tied into the wires directly coming out of the radio, still the noise pursisted. Like you, I started with the basics, checking grounds, disconnecting, reconnecting, and double checking leads until I was stur crazy w/wires.


Duncan

 

The alternator is still working - your battery is not dead! You can replace just the voltage regulator which controls the power flow/charge etc from the Alternator. Lot cheaper than a complete alternator.

Good Luck!

Andy

 

Andy, thanks.

I think that is what I will do, along with some new alt bearings. Think I'll replace the cooling fan bearings too, while it's all out.

Duncan