Hi Tony,

Cue the mists of time....

It all started when I transferred my set up from my trusty old 1986 MK2 Golf 1.3 to my new 1990 MK2 Golf GTI. My set up consists of an Empeg MK2a, one amp running two subs, and another running components in the front. I have stinger triple screened RCAs and 8 gauge ground cable from both amps to a very secure ground.

The trouble started when I picked up a nasty alternator whine which I attributed to a normal ground loop. I double checked all my grounds, cleaned all battery and earth strap points, ran a new ground solely for the Empeg's harness and also running to the sled itself, I was satistied that it wasn't a 'normal' ground loop problem.

I then went after signal. I knew the whine entered the system as a result of docking the empeg, as with the amps powered up, and the Empeg undocked, the noise disappeared. I first tried earthing the RCAs at the amp end knowing that the amps provided a balanced input. No improvement. I then tested the harness to check continuity of the grounds. I discovered that only the rear RCA ground leads were going to ground. So I checked the harness for loose pins, and narrowed it down to something inside the player, I dismantled the player to check the internal connections, and when these tested ok, I removed the main board and started tracing tracks. To my surprise, the front and AUX grounds have nothing connected to them while the rear output has a thick ground connection.

The problem arose because when transferring the system, I decided to run the subs from the rear RCAs and the components from the front RCAs thus separating the grounds that were previously tied together in the old set up.

So I modified the RCA plugs at the head unit end to incorporate two flying ground leads to which I soldered eyelets to and then bolted them to the new ground connection on the back of the sled.

The silence is golden.
Problem solved.

Oli.