I know that this is a subject that has been round the block a few times, but it only just landed on my doorstep! I’ve been largely fitting my own in-car kit for approaching 40 years now, so I thought I knew just about everything.

Before posting, I checked the faq and its links, in great detail.

Since I first received it up until last Monday, the Empeg worked faultlessly in my MGF, when I got back from holiday then, and put it in to go to work, it had a pronounced buzz and whine.

Reasoning that it worked fine in the other dock, and in Mark’s excellent home docking station, I concentrated on the car and its fitting. The obvious conclusion being that a wire had come loose. Given the shortage of space behind the dash, it wouldn’t be surprising for something to snag.

I’ve checked through every wire to the best of my ability and can’t find anything astray.
I checked with a multi-meter to see if there were any obvious ground loops. I removed the harness, cleaned up both the plug and socket with contact cleaner and checked visually that each wire in the harness was connected.

In desperation, I tried disconnecting the tuner, the aux input, the Sony remote stalk: No joy. So, I took it to my pals at the best auto fitting centre in town, who kindly, as they had not done the installation, checked it all over for me.

So, I’m just hoping someone out there has had a similar experience, or can point me in a direction????

While the engine is running, or all the time (when off)?

Also, when paused, or playing?

When the engine is running paused, playing, also on tuner and aux.

Do you have a common grounding point for all the audio gear? Is it properly scraped and greased to ensure a good connection (no salt corrosion or muck)? Can you check for 0 Ohm continuity between player/sled and the battery neg terminal?

Have you checked the state of your battery, as a battery going bad has caused this a few times? Is the alternator charging?

Great Thanks, I probably won't get a chance to check those thing 'till Thursday. The battery is approximately only 11 months old, having given up the ghost in an underground car park in the Hague, on the way back from a certain important meeting!

OK, well don't forget to check the battery cell water levels, and give it a full discharge (headlamps overnight unless it's the type that should not be discharged) and re-charge. Do NOT short circuit it, but then I don' t have to tell you why not.....

So, I’m just hoping someone out there has had a similar experience, or can point me in a direction????

I recently cured a long-term alternator whine by grounding an RCA screen (wedging a small length of wire between the phono plug and amp body).

Only 1 of the 3 pairs of RCA's in my car required grounding to resolve the problem.

So, after 10 days, I drive round to Maplins for some bits and pieces, get back into the car, listen to the whining and buzzing for a few secs. decide that the weather has improved enough to put the hood down, leave the engine running whilst I do so, hop back in and slam the door and all the extraneous noises promptly stop.
Despite coming home on country roads with terrible surfaces, I can't replicate the problem.
I suppose it's not the end of the problem, but probably narrows it to a loose connection, or maybe it's wear and tear on the docking connector, at a quick calculation, it's been in and out a couple of thousand times (No dirty jokes, please!).
But thanks for the help gang, I may very well have to return to the subject.

slam the door and all the extraneous noises promptly stop.

Also consider that the problem could be internal to the empeg, or possibly at the amp...

I corrected a similar problem after discovering that the contact between the sled and the RioCar was less than snug. I had to bend the sled tangs so that there was a more forceful sliding contact when the unit was inserted into the dash.

You might check that the metal "bumps" on your sled are still makng positive contact with the metal shell of your empeg. And that the metal shell in the dash is itself reliably grounded.

Intermittant problems can be a bear to nail down.

Also consider that the problem could be internal to the empeg, or possibly at the amp...

The amps a possibility, but I ruled out the Empeg because it works fine in both my motorhome dock and Mark's home dock.
Trouble is, until it cuts back in (which I'm sure that it will sooner or later), I'm loathe to touch it.

Ho, Hum, Well I dunno, I’ve done everything that you’ve all kindly suggested in this thread, and the noise is no longer intermittent in the MG.

1) Just to be sure, I’ve re-charged the battery in the motorhome and put the Empeg in, it’s absolutely clean up to full volume.
2) I’ve noticed that when I turn the volume up way above listening level in Mark’s dock, I can hear background noises, but not appreciably.
3) If I plug it in to the home supply it’s absolutely clean.
4) I dismantled the sled and took the top off the Empeg, every pin is connecting correctly from inside the HU, through to the back of the sled connector.
5) Where waggling the wires could stop the noise, it no longer does.
6) The battery seems to be holding its charge O.K.
7) I’ve connected the amp to a spare HU, it works fine.
8) I’ve by-passed the fitted negative wiring with 70 amp cable direct to the pin on the dock.

The only thing I’m not sure about is how to check for a fault in the alternator, as I say, it seems to be charging properly.
Any other bright ideas? I’m going to take it back down to the fitting centre on Monday, but as I’ve said, they can’t find anything obvious.
Pity I’m not taking it to Amersfoort, this year, for people to scratch their heads over. But I don’t fancy crossing Yorkshire and Holland with a loud buzzing, anyway.

I don’t fancy crossing Yorkshire and Holland with a loud buzzing

So what do you get when you cross Yorkshire and Holland with a loud buzzing?

BBC America, I think.

Naah, BBC America is always about 6dB quieter than all my other channels.

Naah, BBC America is always about 6dB quieter than all my other channels

I'll not hear a word against the BBC, at about the time that you posted this, I won two tickets to Bonnie Raitt on the late night show on BBC.
I've been trying to think of a witty rejoinder to the cross Yorkshire, Holland, Buzzing post, all night, but it eludes me!

Sounds like a ground loop in the signal connection - you need to insulate the ground conductor of the signal cable as though it were a hot conductor. It should connect the ground of the car player's outputs to the grounds of one or more amplifier inputs, and nothing else.

This means if you have another head-unit you cannot join the grounds of its aux out to the ground of the car player's output. OTOH it is fine to connect any old line source to the car player's aux-in since that has a floating ground.

I made this mistake once trying to use a relay to bypass the car player when it was removed from the sled - I switched the signal conductors and just joined up the grounds of the two sources. You still can do this, but you must switch the grounds too using a 4 pole relay.

Cheers, John