Help! Trying to get rid of a high pitch whine coming from a pioneer head unit and Rockford 200.4 amp. Here is what I have tried...

1. Ground cable. 8 guage 1.5ft good clean connection to the truck body.
2. RCA cable run down passenger side of truck.(power on drivers)
3. Ran seperate RCA from head unit down the middle of truck. Same noise.
4. Different head unit gives same result.

I have tried a Radio shack ground loop isolator. It clears up the whine 100% but gives bad distortion at moderate levels. I also tried a PAC isolator from cicuirt city with better results but distortion is still there.

Any ideas??

Truck is a 2001 Supercrew

Thanks for the help
Chris

 

Try grounding your HU at the same place that your amp is grounded.

Temporarily disconnect all power to your HU (at the fuses). Clip the HU ground wire and splice a temporary wire (at least the same size or larger than the wire coming out of the HU) back to your amp ground location.

Also check your antenna lead to make sure it has a good ground.

Good Luck!

 

I tried to run a dedicated ground from the HU back to the Amp as well. Still have the noise. I will try a different ground position tomorrow.
Anybody see a ground loop isolator out there that does not add distortion???

Thanks for the help

Chris

 

Have you tried another amp?

 

Chubert:

1. Disconnect the antenna. Play a CD. Noise still there ?

If no, check antenna ground. Be sure that the coax isn't nicked or cut and that the fender mount is secure and has a good ground connection.

If yes, isolate the antenna problem by inspecting the coax and mounting hardware very carefully.

2. Does the whine rise and fall with engine RPM ? Do you get the whine without the engine running ?

3. Disconnect the inputs to the amplifier. Do you still have whine ?

Fords are notorius for engine / alternator whine. The best solution I have found is using amps and HU's that have high (4 Volt or more) RCA inputs / outputs.

A visit to your local high-end car audio shop might save you a bunch of grief.

Good luck and let us know what you find out.

 

I have not had time to mess with it the last few days. I will try disconecting the antenna from the HU.
It does rise and fall with engine RPM. No noise without engine running. If I disconnect the RCA's I get no noise.

I will let you know how I make out.

Chris

 

Shorten your grounds as much as possible but if that doesn't fix it possibly theres a prob with your stereo

 

Which end of the RCAs are you disconnecting? Try both ends, one at a time, to make sure that the RCAs are not picking up some induced noise.

 

OK. I think I have it pretty much fixed. I moved the ground (again) to the rear seat mouning bolt on the floor. The ground is longer but the noise is 95% gone.
My ground was on some sheet metal inside the rear compartment of the cab before. I think that sheet metal may have been glued and only tack welded not giving a great connection to the chassis.

Since the other day I also tried Monster twisted pair RCA's and a power filter on the radio. I guess it was the ground all along!!!!

Thanks for all the help.

Chris