Alternator Whine... ?? (from accident or new amps)

[Shane1]

So my 2001 Tahoe was in a 40MPH front head on collision recently. The truck was fixed, frame straightened and it drives perfectly !
I installed some amps, speakers, etc right after and alsu upgraded the audio electrical (Big 5 under the hood w/ 0 gauge, all amps grounded directly to the frame at the rear).

I am getting alternator whine and have isolated it as being sourced from the new Alpine Head unit. The amps and DSP are quiet, but I know its at least coming from the Alpine. All the audio equipment is grounded at the frame in the rear, so they all have a common ground (amps, head unit, DSP all grounded at a bolt to the frame).

Q: Could the alternator whine be as a result of the body shop not putting the truck together correctly? Or could it be as a result of the audio install ??? I installed a new 420A alternator as well.

Just thought I'd reach out to others for input...

Thanks!

 

[Doubeleive]

if you ran your speaker wire and rca's on the same side of the vehicle as the power wire that is the reason for the whine, run power on the drivers side and speaker wires/rca's on the passenger side

 

[Cattivo]

Engine whine can come from touching RCA cables together, they blow tiny little fuses inside the HU which causes the whine...easiest way to get rid of the engine whine is to ground each RCA cable to the HU directly using 18-22 awg wire (preferably)

 

[rockola1971]

So my 2001 Tahoe was in a 40MPH front head on collision recently. The truck was fixed, frame straightened and it drives perfectly !
I installed some amps, speakers, etc right after and alsu upgraded the audio electrical (Big 5 under the hood w/ 0 gauge, all amps grounded directly to the frame at the rear).
Did you run the factory HU before the Alpine change? Did it have whine?

I am getting alternator whine and have isolated it as being sourced from the new Alpine Head unit. The amps and DSP are quiet, but I know its at least coming from the Alpine. All the audio equipment is grounded at the frame in the rear, so they all have a common ground (amps, head unit, DSP all grounded at a bolt to the frame).
Just because "they all have a common ground" doesnt mean its a good ground. Measure resistance between your common ground bolt head to battery negative terminal. You should see less than 6-8 ohms I suspect if all is well.

Q: Could the alternator whine be as a result of the body shop not putting the truck together correctly? Or could it be as a result of the audio install ??? I installed a new 420A alternator as well.
If the shop pulled the body they could have left out some mounting bolts OR not tightened all the way. New alternator could be the culprit. Put a Fluke on it and measure the frequency of the whine and that could prove it to be coming from the alternator. Alternator makes AC and is converted to DC via diodes inside.

Thanks!