I installed my MK2 in my Puma about 4 years ago.
Sound was perfect.

For the last few month I'm having noise problems.
(Alternator whine, etc.)

I know the procedures to spot the problem,
but since everything is hidden deep in the bowels of my car
I'd rather not do it the "classic" way.
(I'd have to take apart almost the whole interiour.)

So let me explain the problem in a bit more detail.
1. Sometimes the sound is perfect. Sometimes it's not.
(A bump in the road or a tight corner can "switch" it on/off.)

2. When I "wiggle" the MK2 it gets better or worse.
3. When I move the handle it changes.
(At about 45 deg I usually get good sound...)

I'm guessing that it is a loose wire in the harness or the unit itself.
Or simply bad/dirty contacts in the connector.

Anything I could/should do before taking my car apart ?

My girl would kill me if I'd spend another weekend with my car instead of her

Looking at your signature and your message, you have an original Mark2 instead of a 2a. The early car sleds that came with the Mark2 had a known problem where the wire leads can (under correct circumstances) pull out of the docking connector. It would be a matter of checking for a loose wire at the docking connector and securing it properly. Unfortunately, that probably means taking the dash apart to get at the back of the sled...

If it's not your sled connectors then it's your ground connection.

Definitely consider a squirt of WD-40 on your docking connector before you invest lots of time taking stuff apart.

Euuuuwww. WD40. That stuff turns to a fine insulator once the volitales burn off.
Use it once, use it for ever and ever and...

Agreed. There is other spray that is meant to clean off those kinds of connectors which doesn't contain dirt-collecting oil.

I finally found some time to debug.

In the end I just had to unplug and replug the RCA jacks ...

Don't ask what happened, but the noise is gone

For the last few month I'm having noise problems.
(Alternator whine, etc.)


Been there, done that!

I recently finished a complete, totally insane restructuring of my stereo, and ended up with system noise (I could hear the hard drives and switching noises from the empeg through the speakers) and rather exceptional alternator whine -- at 70 MPH with the music playing loud enough to overcome wind and road noise, the whine was not only noticeable but quite intrusive over even loud passages of music.

The restructuring consisted of replacing the two amplifiers I had (an 8-channel amp for the "small" speakers and a two-channel amp for the subwoofers) with five separate emplifiers, one for each channel pair in the car, each amplifier with its own remote gain control (potentiometer on the signal input) built into the center arm rest. There's more than 150 feet of RCA cable carrying signal from the head unit(s), going back to the equalizer, up to the remote gain controls where it is split five ways, and then back again to the amps.

Lots of opportunity there to pick up noise.

We think the alternator noise was (of course) a ground loop problem. The amps are mounted to a 5/16" almuminum plate which in turn is mounted on hinges screwed to the chassis of the car. It would appear that the new amps were allowing signal path ground through the chassis of the amp and into the aluminum amp rack, because when we "ungrounded" the amp rack, the noise went down considerably.

But the big improvement came when we realized (Doh!) that splitting the input signal five ways at the remote gain controls just [sarcasm] might [/sarcasm] cause a reduction in voltage at the amp inputs. (Try 8/10 of a volt for your signal input and see how good your stereo sounds!).

We put a line driver in the signal path before the 5-way signal split, cranked it up to just below the clipping point on the amps, and... no more noise. Even re-grounding the amp rack left the system listenable -- there is alternator whine under hard acceleration above 3500 RPM (strangely enough, putting the engine in neutral and revving the engine to 3500 RPM produces no whine) but if I didn't tell you what to listen for and when to listen for it you would never hear it.

I'm not claiming that a line driver will be the panacea for every type of system noise, but in my case it certainly helped. (Are you listening, edsmiata?)

tanstaafl.

HAHAHAHA!

I was actually looking into putting a line driver in...but i thought the opposite would happen...it would crank up the noise considerably!

I dont have the magnitude of wires you have..but i do have 2 amps
2 head units
1 sat radio receiver

everything is peachy now unless i draw considerably on the alternator (A/C, rear defogger (esp))

I understand that with the Miata tha alternator only kicks in when there is a heavy load...it is not 'on' all the time

so..at least for now...the top is down and the only noise i hear is the wind!

i can deal with that for now...ask me in November!

Thanks for the heads up!