^ thats pretty much the first thing I thought of... more current to the bat from cold windings at a higher voltage = more whine... a batt will also filter AC ripple so if your alt is acting up when its cold you it could be putting some AC right into the electrical and who knows what that could do... it could also be a fault in your deck too I suppose... ect ect

I think you'd probably need at least a few hours of testing and oscope to really troubleshoot this and narrow down the cause... so Id say just use one of several fixes for alt whine in general and call it a day...

 

well it's not the deck, brand new alpine

it maybe due to less than great RCA's

also i'm going to shorten the ground on the speaker amp, just kinda coiled in the spare trunk "hole"...any reason a coiled ground wire would be bad?

 

you need to rethink your Q

and that is

can a ground wire would be bad ? YES REDO THEM .

 

sorry replace "would" and put in wound


the ground wire is rolled up and is just sitting in the spare tire well

 

I know what you're talking about, the alt noise from the stereo only when its really cold. I had that in my old car. I finally fixed it after 3 winters of putting up with it.
I replaced the power and ground wires and found corrosion in the crimp lugs.
It turned out that the lugs were actually loose when it was that cold because the wire shrinks.
check any and all crimps. solder if possible. noise will go away.

 

where abouts?

i have no crimps/solders anywhere except at the new harness, those are all good

lugs?? please explain

thanks

 

Is the Sound comming through your tweeters more? Well just to let you know your not crazy!

I live in thunder bay where for a while we had -40 every mornin.

I have wrestled with my whine for less than a year now and have done quite a bit to eleviate it. Every time i fix it, when it gets **** *** cold it comes back.

Here are some steps I recomend so far.

1.) Give your headunit a nice clean ground. this DOES NOT mean re run it to negative terminal of battery i tried that but in passing through the fire wall by my power it induced alot more noise. A nice chassis ground below the dash should work fine. Possibly even run a small wire from HU chassis to the HU ground.

2.) MAKE SURE ALL AMPS HAVE THE SAME GROUND

3.) Possibly Fabricate a RCA low pass filter Circuit. I have done this by taking scrap jacks off of an old VCR or TV. Get ahold of 2 .1 micro farad capacitors (any type), one for each channel and run it from signal to signal ground. MAKE SURE all your solders are nice or else you back to square one. once your done fabricating and you know you got it right, silicone the out of it so it wont short. This step helped me alot.

4.)Ground the Chassis of your amps to the same ground the amps share.


Also as another note, im using a 2 component filter which has a capacitor and a inductor.
WARNING your inductors will act as little antenneas and WILL pick up any EMI from Class D amplifiers, Neon Light Ballasts, EL wire Ballasts, and a whole wack of other stuff.

A solution to this is the isolation of your fileter circuit from the radiation rich environment of you trunk via a Radio Cage. But i think if talked to much. If anyone is interested in any more PM me!

PEace

 

Ive never heard of adding capacitance to an RCA


Personally I would go with one of the many fixes from David Navone - Car Audio Engineering

 

Well frankly I think it is just a bit of frozen or precipitated moisture on the amp or HU. As the system heats up it goes away... try this: when you hear the whine with the engine running turn off the car but leave the stereo on for the usual 5 minutes or so (go ahead and play it loud), then turn the car on and if the whine is gone the HU or amp is probably the source of the noise. Moisture source could be a leaky trunk, firewall, moisture from your boots etc.

I suppose it could be from moisture under the hood but my issues have been with the vehicles interior

 

that looks right