intermittent open ground noise

[Johnb21]

I have a 2005 LT and have been chasing my tail on this one for almost 2yrs.
I have an aftermarket Pioneer DVD with adapter running to the stock Bose, not premium, amp. During the winter/spring months, the deck will put out a ground loop whining noise (increases with rpm). I have removed the deck from the dash upwards of 10x, trying to resolve the problem. I have run special grounds for the deck, replaced the changed the alternator (needed to anyway), and checked every connection. Symptoms, when you hit a bump/pothole, the noise comes on, or if already present, it will sometimes go away. This can be replicated by banging on the dash. You can also make the noise go away for a short period by cycling the deck off/on. It only happens during the cold months (I live in the Boston area). I can't find any loose wiring. I had come to the conclusion it was some electric component in the deck itself, until recently I was thinking it could be the Bose amp. Anyone have any advice or thoughts here? Much appreciated.

 

[Gary II]

I have a 2005 LT and have been chasing my tail on this one for almost 2yrs.
I have an aftermarket Pioneer DVD with adapter running to the stock Bose, not premium, amp. During the winter/spring months, the deck will put out a ground loop whining noise (increases with rpm). I have removed the deck from the dash upwards of 10x, trying to resolve the problem. I have run special grounds for the deck, replaced the changed the alternator (needed to anyway), and checked every connection. Symptoms, when you hit a bump/pothole, the noise comes on, or if already present, it will sometimes go away. This can be replicated by banging on the dash. You can also make the noise go away for a short period by cycling the deck off/on. It only happens during the cold months (I live in the Boston area). I can't find any loose wiring. I had come to the conclusion it was some electric component in the deck itself, until recently I was thinking it could be the Bose amp. Anyone have any advice or thoughts here? Much appreciated.

I had the same problem. I found that running a new 12v, ground, and acc wiring from the head unit fixed mine.

 

[Johnb21]

Thanks Gary. Did you have exactly the same problem? I only have these issues during cold or damp days.
I did run an extra ground to the chassis of the head unit, but that is it. Thanks!

 

[David Paul]

I had the same type intermittent problem when I put my Alpine HU in. Didn't start right away after the install. Put an additional ground to radio chassis. No change. Remove HU again, put dialetric grease on each connector to HU and adaptors for OEM wiring, problem solved.

 

[Johnb21]

I had the same type intermittent problem when I put my Alpine HU in. Didn't start right away after the install. Put an additional ground to radio chassis. No change. Remove HU again, put dialetric grease on each connector to HU and adaptors for OEM wiring, problem solved.

That's interesting...I can't recall if I tried the dielectric grease or not. I have had the HU out so many times. Worth a shot to go back in and apply some grease. Thanks David.

 

[Johnb21]

I had the same type intermittent problem when I put my Alpine HU in. Didn't start right away after the install. Put an additional ground to radio chassis. No change. Remove HU again, put dialetric grease on each connector to HU and adaptors for OEM wiring, problem solved.

BTW, did banging the dash or cycling the deck resolve the issue temporarily? Just curious to how similar your symptoms were. thanks.

 

[David Paul]

BTW, did banging the dash or cycling the deck resolve the issue temporarily? Just curious to how similar your symptoms were. thanks.

Never banged on the dash, but on occasion hitting a bump would either stop it or start it. Seemed to come from the right speaker the most. If I turned it off then back on, sometimes I'd hear it some times not. I had it out once to put in the additional ground that seemed to work for a week or so. Took it out once again, greased all the conections, hasn't returned for the last three months. It seems pretty similar to your issue. It's a long shot, but hey, easy enough and the price is right...
Good luck

Oh I'm also using the stock amp so I think the conections are the same as yours.....

 

[Cattivo]

Pioneer HU's are notorious for engine whining, if you're using rca's from the HU back to the amp and can hear engine whining every time you hit the gas this means you blew a tiny fuse inside the HU

Quick and easy fix...take some #12 awg speaker wire about 5-6'' long, strip the plastic/rubber jacket completely off of the wire, make a small 90* bend at the end of the wire...hook it inside the rca connector without it touching the center pin and using electrical tape, tape it in place.

Slide the rca jack back into the HU and ground the other end of the bare #12 awg wire to either the metal frame of your HU or a good source of ground.

Repeat these steps on all your rca connectors
(ON THE HU SIDE ONLY) and you are guaranteed to never have engine whining again

 

[Johnb21]

An update. I bought a new HU (Pioneer NEX-4200) and I though I had resolved my problem. Two months later and the ground loop noise is back. Again, the noise is intermittent, but there more often than not. One new detail, as the noise is really only coming out of the front drivers speaker (both midrange and tweeter). I can hear a slight sound from the rear left passenger, but you have to put your ear on the speaker grill to hear it. Other details, the volume of the noise doesn't change when turning the HU volume up or down. The pitch of the noise in the drivers side speaker does change with rpm. I have not proceeded to rewire the 12v and ground, as I am not convinced this will resolve the issue. Mainly because the noise is coming from just the driver's door speaker versus all of them.
Banging on the dash doesn't make the problem go away anymore, but bumps in the road do still set off the noise.

Any other thoughts? I am going to look at the connections at the Bose amp again. Thanks!