Okay, so I've installed my new H/U (Clarion NX500) in my 2008 Dodge Ram, and I've got faint alternator whine when revving the engine.
Here's what my configuration was before the install (there was no alternator whine):
- Factory Head Unit
- Audiobahn A4004T Ampifier under the driver's seat
- New heavy duty speaker wiring run directly from the AMP to all 4 door speakers.
- tapped into the factory speaker wires from the side of the car to get the audio to the amplifier.
Here's what the latest install included:
- Installed the Clarion NX500 (replaced the dash bezel with the NAV bezel to maintain a clean, facory look.
- Used a bypass that I got off ebay to bypass the brake connection ( to allow full functionality when the parking brake is off).
- used the PAC harness from Crutchfield.
- connected RCA cables (SCOSHE cables from Wal-Mart directly from the H/U outputs to the Amplifier inputs.
- Used the factory harness ground to connect the NX500 ground to (I know this is less than ideal, and if needed I can remove this wire, and connect to a better ground, but I want to work through some troubleshooting and know this is neccessary before doing this.
Here's what I've done so far to troubleshoot the whine:
- Removal of the RCA cables from the amplifier does not stop the alternator whine.
- Removal of the RCA cables, and replacing them with shorting plugs as suggested here (http://decibelcar.com/index.php/menu...65-enginenoise
) does elliminate the alternator whine.
- Installation of two ground loop isloators behind the H/U between the Head Unit and the Amplifier actually makes the whine worse (that shocked me).
- Checked the ground on the amplifier -- it's currently connected to one of the bolds holding the seat down to the body.
I'm not sure where to go now -- since testing with the shorting plugs elliminated the alternator whine, I have to assume that it's coming from either the H/U or the RCA cables.
Would it make sense to plug the shorting plugs into the RCA cables behind the H/U to determine if it's coming from the RCA cables or the Head Unit?
Also, why would the noise persist when there is nothing plugged into the amp, but stop with the shorting cables? Does this tell me anything? Or is the noise just being picked up somehow by the RCA inputs of the Amplifier?
This is driving me crazy, hopefully with the steps outlined above somebody can shed some light into the next best step...
Btw, I absolutely love the Clarion NX500 - I put the GPS antenna in the center speaker hold. I used a faceplate (cut it up to fit in the speaker) attached to the speaker mounting holes (the holes in the faceplace or 3.5" wide -- the same as the speaker bracket - very cool) and then put the gps antenna on the faceplate and taped it down. I have excellent reception with the gps antenna in that location.
Thanks so much!!