The latest in my saga:

I have the Rio installed in my Miata along with a Sony head unit, an MTX 4ch amp and an Alpine amp.

The Sony goes into the Aux on the Rio.

The Rio is grounded to a separate grounding point in the trunk, where the MTX is also grounded.

The Rio harness and the Sony are both grounded to the original grounding point of the stock Bose HU.

Here's the deal:

All was working fine, very clear, no noise, until one day the whine came back. This also coincided with the dreaded "Hard Drive Not Found" display, which I traced to a dry solder joint on the mother board.

Fixed that pin but the whine remains.

However, if I hook the Sony up straight to the Amps, thus bypassing the Rio, there is absolutely no noise at all! It is only when I run the outputs of the Rio to the amps that I get the whine.

It is too coincidental that the dry solder problem and the ignition whine both happened at about the same time.

Looking at all the other joints I notice that they too may not be getting as full a contact as perhaps they should. But the Rio boots up just the same, no problem.

So if I may ask once again for you all to put your thinking cps on and givent he wiring I described above, at which connection am I picking up this horrible whince?


Thanks,

Ed

Be certain your sled is also grounded well. That's my $0.02. Obligatory FAQ link.

-Zeke

Usually engine noise is due to a loose connection somewhere, typically a ground wire. Every once in a blue moon it's a bad alternator or voltage regulater, or some other random crap, but from what I've seen that's not the norm.

I would try pulling the sled out far enough so that you can get to the cables, and then fiddle with all the connections while it's playing. Just be careful not to ground out a 12v lead or anything. (No power wires should be exposed, but it never hurts to be careful.)

More than likely, you'll find there's one connection back there somewhere that's just a little sketchy.

I had the exact same problem with my empeg. On my unit, it was where the cables connect to the molex on the back of the sled.

The Rio is grounded to a separate grounding point in the trunk, where the MTX is also grounded.

The Rio harness and the Sony are both grounded to the original grounding point of the stock Bose HU.

The above statements contradict each other. Which place is the Rio grounded to? The stock wiring point or the grounding point in the trunk? You say Rio twice. Which is it?

Anyway...

Remember the following:

The electrons are going to try to take the easiest route to ground. If you have a tiny skinny little wire grounding the head unit (ie the factory wire), and a fat wire grounding the amp, the electrons might choose to go down the RCA cable to the amp.

Conversely, if you have a crappy grounding point for the amp in the trunk (for example, you've grounded it to a strut that is spot-welded in place instead of to the floor pan), then perhaps that ground is less good than the one for the head unit, and the electrons are going to go up the RCA cable to the head unit.

At any point, if there is a loose connection or a cheap piece of wire, then that's going to be your bad ground point and that's going to cause noise.

I have grounded the Head Unit to a point in the trunk and the sled to the ground terminal for the original head unit. Thus, I have two separate grounds for the rio: one for the HU itself and one for the sled.

What is interesting, though, is that when i take the RCA's leading from the Rio to the Amps and plug them directly into the Sony, I get no whine at all. (Bypassing the Rio Aux)

So perhaps, as I am now thinking about it, the ground wire from the Rio HU and not the sled, is compromised and I shoud re-run that?

I've seen a couple people with this problem...try grounding your RCA cables as they go into the amp. It'll work wonders. Interestingly enough, the guy I know with this problem is running a Sony head unit into his AUX on his Empeg and two amps and he also got no alternator whine with just the Sony.

Danger Will Robinson, Danger. 2 different grond points for the Rio and the sled? That's a potential issue right there. You should also never grounf a head unit to any point in the trunk. Dont run long ground wires. Always make sure your grounding wires are at least as thick as your 12v wires. Keep them as short as possible. Keep a common ground if possible (in the case of using amps, keep those grounded in the trunk and HU's grounded together in the front). In your case, ground all Rio parts and Sony to the same place in the dash area. The original factory ground point may not be good. Make sure you have bare metal contact with a quality piece of metal. Bruno

I also get engine whine as well. My Empeg is plugged into the AUX in of my Blaupunkt HU. When I have the empeg in its sled, I get engine whine. When it's out, I hear no whine at all so it's definitely somewhere in the wiring of that sled.

I found that having a common amp/Rio ground, power taken from the vehicle harness (not the ignition) and, most especially, ensuring the amp was on 4ch and not 2ch, made a significant difference. (a 4ch amp in 2ch mode usually uses the extra phonos as bridging outputs, potentially routing straight back into the Empeg unit...)

exactly my issue!

The interesting thing is that i had originally grounded the sled to the grounding point in the trunk where the HU was grounded. Nothing changes (i.e. whine!)

On a lark, I jambed a wire between the sled and the HU and touched the metal ring of my cig lighter..and the whine disappeared!

this lasted for a few months until one of the pins on the mother board from the IDE cable plug dried up....get the No Hard Disc Found display..doldered the joint back..but the whine did not go away!

So now, when I run the RC's to the Sony and bypass the Rio..crystal clear..when i run the Sony into the Rio and run the RCA's out o the Rio and into the Amp..i get whine....

so maybe i need to re-run the ground from the Rio to the front of the car from the rear where the amps are grounded?

Should I then run 3-grounds..the Rio, the Sony and the sled all to one point in the front (original wiring harness ground or separate?)

Thanks!

Also, how does one go about grounding RCA cables,a s it was suggested where they go into the amp?

Ed

Your interconnects are already grounded at the amplifier and/or preamp (head unit).

Bruno

I seem to be suffering from alternator whine too. At the moment the sled is not grounded, the harness is obviously otherwise it wouldn't even switch on! So I think I'll try grounding to that. The Rio is connected via a fuse directly to the battery. It's still using the original ground point from the car harness.

Ok, here is what I did..

i cut the ground wire from the rio to within several inces of the harness...and connected it to nothing!!

The whine went away...so all i have grounded now is the sled and the sony to the stock wiring harness ground point

i orignally had the ground from the rio running along the door into the trunk and grounded to where the amps are grounded..

now the rio is not grounded and all is fine!

go figure!

the only other thing worthy of mention is that I've got one of Robs black sleds. I think I'll ground the sled tomorrow and take it from there...

i agree...it is definately a source of noise