HU Switches Sources on it's Own! Help?!

[Vipervenom18 10+ year member]

Hey everybody. Just fully installed my system which was a PITA this time around. Finally got everything working, and now just have one more annoying thing to diagnose and everything will be 100%...

The HU I have is a Pioneer AVH-P3300BT.

Long story short, whenever I turn up the volume when listening to a song, my head unit will switch sources on me. It's as if I pressed the "source" button, thus switching to the next source.

Aka if I am listening to a CD on decently loud volume (anything above 65% volume, roughly), the HU will switch to the iPod source randomly. If I'm listening to my iPod, then it will switch to the radio (which is the next available source) etc... I'm obviously not hitting any buttons when I do this.

Things I've unprofessionally ruled out:

- Both my amps gains are set correctly (actually very conservatively). I have a 4 channel amp powering 4 pairs of comps, and a mono amp powering two subs. Neither one of them is clipping when volume is turned up. The clip indicators don't even show anything either, and both amps aren't even close to getting warm. Even if the amps did go in protect (which they aren't) this wouldn't change the source on the HU.

-I don't think its my bass vibrating anything inside the Head Unit to make it malfunction. This is what I thought it was (turning up the volume aka the bass shaking the head unit around.) But then I played a rock song with little bass and it still did it.

-Maybe the HU is getting warm and malfunctioning? If I turn up the volume right away when I start the car it usually takes a song or two for it to malfunction and switch the source input. Then once it happens it will continually switch sources if the volume is above 70% intermediately. I recently had to take my entire dash apart to replace my heater core which allowed me to get to the back of the HU. When I turned the stereo on the HU never seemed to get warmer than normal.

-Any other ideas? Is this a protective feature or something I don't know about? If I am listening to a CD and it switches sources to iPod randomly, and I immediately change it back to CD everything plays fine (up until it happens again in a few minutes...)

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I'm stumped and have never run into this before. Any input would be much appreciated.

PS... My friend who owns a shop and I went around the entire car and stereo with a multimeter checking shorts, voltage levels, current flow, fuses, etc etc etc on everything connected to my stereo, and everything seems to be tip-top.

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[Vipervenom18 10+ year member]

Yeah... I'm stumped too... Haha

 

[Rich B 5,000+ posts]

Exorcism is the only answer.

 

[Vipervenom18 10+ year member]

LOL, this is just the most random thing that has happened in any of my installs. I have absolutely no clue on how to fix it.

 

[cyn 10+ year member]

you got a ghost that likes to jam out man... get a priest or preacher out there to get rid of it lol

 

[Vipervenom18 10+ year member]

LOL, I appreciate the jokes. It shows that this makes no sense.

One thing I forgot to mention in my original post: I have a remote adapter so my factory steering wheel controls can work with my aftermarket HU. I'm wondering if this thing somehow messes with the stereo, as one of the buttons/functions is to change the source! (Along with volume up/down.)

But the volume never changes, just the source.

 

[VWBobby 10+ year member]

I had a similar problem with a Kenwood unit I installed recently. It would power off and back on if I had the volume higher than about 50%. It turns out that I had a bad ground and would only show when I was drawing enough power (volume cranked). After making a new clean ground, problem resolved. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Its also possible that your HU is pulling ground/positive from your steering wheel control and disconnecting it would show this issue.

 

[Vipervenom18 10+ year member]

I had a similar problem with a Kenwood unit I installed recently. It would power off and back on if I had the volume higher than about 50%. It turns out that I had a bad ground and would only show when I was drawing enough power (volume cranked). After making a new clean ground, problem resolved. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
Its also possible that your HU is pulling ground/positive from your steering wheel control and disconnecting it would show this issue.

Awesome thanks for a legit post!

1. Was the bad ground on the stereo head unit itself or one of the amp grounds? When system is cranked the lights don't even dim and voltage doesn't drop much. Did the Big 3 which seemed to do good things.

2. I'm not sure what you mean by your last sentence. I'm kind of a newb. Can you clarify?

Thank you so much!

 

[Spike243 10+ year member]

Awesome thanks for a legit post!
1. Was the bad ground on the stereo head unit itself or one of the amp grounds? When system is cranked the lights don't even dim and voltage doesn't drop much. Did the Big 3 which seemed to do good things.

2. I'm not sure what you mean by your last sentence. I'm kind of a newb. Can you clarify?

Thank you so much!

1. He means the ground on your head unit that provides power.

2. If you have a bad head unit ground then it is possible that it is trying to pull power from the steering wheel controls and thus causing problems

 

[maylar 10+ year member]

LOL, I appreciate the jokes. It shows that this makes no sense.
One thing I forgot to mention in my original post: I have a remote adapter so my factory steering wheel controls can work with my aftermarket HU. I'm wondering if this thing somehow messes with the stereo, as one of the buttons/functions is to change the source! (Along with volume up/down.)

But the volume never changes, just the source.

When I read your post I was gonna ask if you had a steering wheel interface. I would suspect that long before the HU. Is it easy to unplug?

 

[Worlddre 5,000+ posts]

Does your bluetooth work properly? If not the steering wheel control input on the back of that unit is a 3.5mm port as is the bluetooth mic input. It is possible that the two are mixed up and when the mic picks up a noise it is sending a signal back to that steering wheel input that mimics the source change.

 

[Vipervenom18 10+ year member]

1. He means the ground on your head unit that provides power.
2. If you have a bad head unit ground then it is possible that it is trying to pull power from the steering wheel controls and thus causing problems

Thanks for the info. I'll jot this down.

When I read your post I was gonna ask if you had a steering wheel interface. I would suspect that long before the HU. Is it easy to unplug?

I bought my first steering wheel interface from Amazon and it was DOA. So I had my friend at his shop just install one of his for me while he was doing other things and it seemed to work (except for this issue I'm having if it's related.)

Does your bluetooth work properly? If not the steering wheel control input on the back of that unit is a 3.5mm port as is the bluetooth mic input. It is possible that the two are mixed up and when the mic picks up a noise it is sending a signal back to that steering wheel input that mimics the source change.

I'll check this out as well, but my bluetooth works flawlessly with my iPhone and I doubt I mixed up the connections but I can check it out. I mean wouldn't my bluetooth not work at all if the mic was not connected correctly?

Besides this issue everything works perfect.

 

[VWBobby 10+ year member]

Sounds like your bluetooth is installed properly if it works flawlessly as you say. I wouldn't suspect that.

1) Start by disconnecting your steering wheel interface/control. Does the problem go away now? It's gotta be the interface or a connection to the interface.

2) If disconnecting the steering wheel controls doesn't solve the problem. Make sure your head unit ground is clean and solid. If the HU doesn't get a solid ground, it will try to pull ground from one of the other wires, like I said in the post above. That's what was happening in my situation, my headunit was pulling ground from the RCA's when I would unplug them, the HU would power off. Now that I have a good ground, I have zero issues. My HU never dimmed or showed signs of a bad ground, other than shutting off when the volume was turned up past half-way. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[Vipervenom18 10+ year member]

Thanks for the tips. I'll update this thread if I get it worked out or not.

I have a feeling that it has to do with the steering wheel controls as its a source change that malfunctions instead of the HU itself powering off or something of the like.

 

[Alexandergrant33]

Thanks for the tips. I'll update this thread if I get it worked out or not.

I have a feeling that it has to do with the steering wheel controls as its a source change that malfunctions instead of the HU itself powering off or something of the like.

What ended up being the problem??? I'm having a very similar problem now