Nasty Whine!

Slippin3 · Post by **Slippin3** » Wed Jul 15, 2009 5:23 pm

Hey Guys,

I have had this ever since I wired up the system, and have started trouble shooting, and its driving me nuts!

When The unit powers on (even with engine off), I get a loud pitch whine through all speakers. Here are some general setup details, and troubleshooting done:

1. System - Pioneer Avic F90BT. PG RSD 500.4 Amp. PG RSDc 6.5" Comp set. Redtop Batt.
2. 0ga wiring for + and - all the way to the back. 14ga for speakers, and DBLink/Monster RCAs (most is for more gear)
3. When RCA is unplugged from amp, noise gone
4. When RCA is unplugged from deck only, noise gone
5. If you touch the male portion of the RCA to the deck chassis, noise!
6. All Power/Ground is on one side of the car, and signal on the other.
7. Battery to Chassis is 0ga
8. Deck is ground to Chassis Ground going into OEM deck harness (larger wire than the Metra kit)

Thanks
John

wash with gasoline · Post by **wash with gasoline** » Wed Jul 15, 2009 6:00 pm

i would try a diff way of grounding the deck, ive had problems with factory radio ground wires in the past. maybe try running a wire willy nilly from the deck ground to your ground point at the amps and see if it goes away. if it does then rout it nicely with the rest of your wires, if not keep looking

Post by **mr tibbs** » Wed Jul 15, 2009 6:22 pm

1) Try different RCA's

2) It sounds like it is the old cold solder problem with the Pioneer headunits. Look around a few different sites for ways to solve this. IIRC you have to ground the outside of the RCA to the chassis of the HU or something like that.

3) I would definitely be looking at your headunit as being the problem. It could be the ground of the HU also as already stated. But to me it sounds like the HU is inducing the noise.

Post by **ttocs** » Wed Jul 15, 2009 7:01 pm

I was leaning towards some bad rca's as well. Try running a temp set above the carpet and see what happens.

Slippin3 · Post by **Slippin3** » Wed Jul 15, 2009 7:05 pm

Well... at the risk of sounding like an idiot, here it goes:

1. I ran a ground from the deck, to the Batt. Still noise. However, when I unhooked from the Batt, the deck was still on?! Trust me... black wire right from the back of the deck was plugged into nothing!

2. I made a "hook" in a piece of speaker wire, and jammed it in the rca, but them together, and grounded them both. STILL NOISE!

This will be the death of me!

-John

Slippin3 · Post by **Slippin3** » Wed Jul 15, 2009 7:06 pm

Diff RCA didnt solve the issue either. Tried 2 more sets.

Post by **ttocs** » Wed Jul 15, 2009 8:23 pm

by unplugging the rca's and connecting the pins you made what is called a grounding cap and it is actually the next step that we needed to do. With the noise continuing with the rcas grounded it would lead me to say the amp is bad.

The only other thing to try, is to try grounding the outer shield of the rca. You can do this by simply wedging a piece of wire between the connectors and then grounding the wire. Be sure not to get it into the center tap of the rca when doing this.

Slippin3 · Post by **Slippin3** » Thu Jul 16, 2009 3:19 am

Thats what I did in step 2.

longboard · Post by **longboard** » Thu Jul 16, 2009 3:56 am

when you pulled the neg i bet the unit earthed via the radio aerial usuall case!

didnt pioneer have problems with the earth trace on the rca outputs on the deck id pull the head unit apart and check the tracks on the board for the rca outputs being good if there not it will cause allsorts of noise!

Post by **smgreen20** » Thu Jul 16, 2009 4:14 am

W/the ground wire disconnected from the HU, see if the whine is still there. Your HU is grounding through the case/chassis completing the circuit. When you add the ground wire it could be making a ground loop.

Slippin3 · Post by **Slippin3** » Thu Jul 16, 2009 4:50 am

Whine is still there with the ground disconnected.

If I touch the RCA male end to the chassis, I get the noise.

Slippin3 · Post by **Slippin3** » Thu Jul 16, 2009 4:53 am

hate to say it.... i may grab a ground loop isolator and see how that does

Post by **ttocs** » Thu Jul 16, 2009 5:45 am

touching the male end to your finger or to ground will often produce noise, that is not a big deal.

If you suspect that it might be grounding through the antenna an easy way to check is to disconnect the antenna.

Try a different audio source both from the front and rear of the car. Get a mp3 player or cd player with headphone to rca outputs and hook it up both in front and rear. If you still have noise you can rule out your head unit.

Post by **mr tibbs** » Thu Jul 16, 2009 6:08 pm

ttocs is on the right track. Try a different source, then a different amp if possible and necessary.

And just to double check, there is nothing in the chain between the HU and amp correct?

Post by **mr tibbs** » Thu Jul 16, 2009 6:10 pm

Also, when you tried different RCA's did you run them the same way or just throw them through the car to the amp?

Post by **Bfowler** » Thu Jul 16, 2009 11:03 pm

i have always had luck grounding the deck to the same spot as the amps also...might be worth trying. you could run a wire over the seats to check...

knightrider358 · Post by **knightrider358** » Fri Jul 17, 2009 6:39 am

try a different ground on the antenna at HU or at the antenna itself also try a direct ground off the chassis of the HU ie directly bolted to HU and also if you have some factory wiring ran on that one side of the car along with the rca's theres a chance one of them may be a constant hot but if urs rca's arent protected enough they will pick up that field from that one or more hot wires so the best bet to run ur rca's would be down the center where there may not be any wires or safest bet is to run them in the roof of the car on either side that would be 100% no noise pick up

Post by **ttocs** » Fri Jul 17, 2009 6:40 am

Bfowler wrote:i have always had luck grounding the deck to the same spot as the amps also...might be worth trying. you could run a wire over the seats to check...

This is also a good "last resort" way. One shop I worked at would run a seperate braid of wires with the remote turn-on wire, as well as a constant and ground to go to the deck on the power side of the car. This way the deck had power and ground from the exact same location as the amps and reduced ground loops. We never did chase noise problems in that shop but with the caliber of cars we worked on and the equpiment we installed there should never be.....

Slippin3 · Post by **Slippin3** » Fri Jul 17, 2009 5:31 pm

Hey Guys,

Thanks for all of the help!

I tried it out again today, and the symptom is a little different, and interesting, so I thought I would share.

When I turn the key ON, I get the whine for about 5-7seconds, and it fades out, and goes away. This is good! It used to whine all the time... during music, when volume was at 0 etc. Its almost like its flushing crap out of the wiring.... lol. I know, that makes no sense, but it illustrates the point

So, I am done! I can live with that for now. The sub enclosure is all glassed, just waiting for it to be Carbon Fibered

Thanks!
John

Post by **mr tibbs** » Fri Jul 17, 2009 7:16 pm

More and more this sounds like a ground issue, either at the amp or the headunit.