New amp constantly on (won't turn off)

[Brunoandrade98]

Hi all,

I've recently bought an amp (Pioneer GM-D1004) for my 197.
It's supposed to be a straight forward install, but I'm running into an issue where the amp is constantly on when plugged into the car harness, and won't go off when the ignition is off and the car locked, even.
It's also constantly on whether the head unit (Pioneer MVH-S420BT) is on or off, or even not plugged in to the amp at all.

In the harness that connects the car harness to the amp, the blue and white wire is apparently responsible for turning the amp on and off with the head unit. That wire connects to a green wire on the car harness and measures between 8-9V whether the ignition is on or off. Is this correct? (see pictures)

Something isn't right, here, and I have no idea what.

And the strangest thing is that I've been struggling with this issue ever since I got the amp and yesterday, for some reason, it worked and would turn on with the ignition on only.
Although, when I turned the ignition off, it would sometimes come on and off a couple of times before going off. I was fine with this, and installed it in its permanent location behind the glove box, and now the issue is back...

I was wondering if anyone could be of assistance, here, as I'm lost.

I explained myself as best as I could, but if you need any more info, I'm happy to provide.

Thanks in advance

 

[Frank Perry]

I had a Pioneer unit fitted with a JL Audio Amp and Sub and it was perfect. Head unit would turn on when ignition powered on, amp was connected to the remote cable on the ISO harness (provided with the Pioneer HU). I have done a fair few sub/amp installs and it was flawless for ~4 years until I stripped it all out.

before you start the below - have you removed the guts under your drivers seat?

I would start with the basics;
1) Does your headunit power on and off when the car ignition turns on/off respectively?
If YES - Move to step 2. If NO - you have a wiring issue and may need to swap the red/yellow cables (constant live and ignition) and see if this resolves the issue.

2) Identify and test the signal in the remote cable. Remote is a ~12v signal cable that goes from the head unit to the amplifier (usually a solid blue cable and tends to come in blue when purchasing a wiring kit). This will only show ~12v when your headunit powers ON and is used to send the signal to your amp to turn it ON. Can you identify this cable using a multi-meter and is it working correctly by testing with a multi-meter? Test: Turn ignition ON and check for 12v signal - turn ignition OFF, does it return to 0v?
If YES - You shouldn't have any issues. Move to step 3. If NO - You have a wiring issue somewhere at the point and will need to continue troubleshooting.

3) Are your cables connected correctly on your amp?
GND - Ground. Usually a short chunky black cable that needs to connect to bare metal surface, usually a belt buckle bolt or something similar.
Rem - The thin blue remote cable that carries the ~12v signal to tell your amp to power on/off - runs from the back of the head unit to the amp.
PWR - The chunky red cable that runs from your battery (with a fuse that should be under the bonnet end) to the amp.

I have seen some poorly installed amps where a strand or two of copper cable from the PWR has been touching the REM and causes the amp to remain on 24/7....

I can't think of anything else on the above - if you're local to Bristol, I'd be happy to take a look, otherwise provide some more photos of the rear of the head unit (when everything is connected) and cabling and connections on amp etc...

 

[Frank Perry]

Also - is that a connects2 adapter you have in the first pic? If so, pull it out and just work with the basics for the moment, get it sorted without the steering wheel controls for now and once you're happy it's working without, we can get that plumbed in afterwards?

 

[Brunoandrade98]

I had a Pioneer unit fitted with a JL Audio Amp and Sub and it was perfect. Head unit would turn on when ignition powered on, amp was connected to the remote cable on the ISO harness (provided with the Pioneer HU). I have done a fair few sub/amp installs and it was flawless for ~4 years until I stripped it all out.

before you start the below - have you removed the guts under your drivers seat?

I would start with the basics;
1) Does your headunit power on and off when the car ignition turns on/off respectively?
If YES - Move to step 2. If NO - you have a wiring issue and may need to swap the red/yellow cables (constant live and ignition) and see if this resolves the issue.

2) Identify and test the signal in the remote cable. Remote is a ~12v signal cable that goes from the head unit to the amplifier (usually a solid blue cable and tends to come in blue when purchasing a wiring kit). This will only show ~12v when your headunit powers ON and is used to send the signal to your amp to turn it ON. Can you identify this cable using a multi-meter and is it working correctly by testing with a multi-meter? Test: Turn ignition ON and check for 12v signal - turn ignition OFF, does it return to 0v?
If YES - You shouldn't have any issues. Move to step 3. If NO - You have a wiring issue somewhere at the point and will need to continue troubleshooting.

3) Are your cables connected correctly on your amp?
GND - Ground. Usually a short chunky black cable that needs to connect to bare metal surface, usually a belt buckle bolt or something similar.
Rem - The thin blue remote cable that carries the ~12v signal to tell your amp to power on/off - runs from the back of the head unit to the amp.
PWR - The chunky red cable that runs from your battery (with a fuse that should be under the bonnet end) to the amp.

I have seen some poorly installed amps where a strand or two of copper cable from the PWR has been touching the REM and causes the amp to remain on 24/7....

I can't think of anything else on the above - if you're local to Bristol, I'd be happy to take a look, otherwise provide some more photos of the rear of the head unit (when everything is connected) and cabling and connections on amp etc...

I really appreciate the help.

At the moment, I'm only powering the amp by connecting the power harness to the car, which also connects to the head unit (see attached photo and file name). The amp should have the basic functionality of turning on and off with the ignition with only this harness connected. It also helps keeping things simple in the meantime.

And yes, that is indeed a Connects2 harness, which I thought was the culprit at one point, too. I've removed it and am not using it in the meantime.

To answer the other questions:

1. Head Unit does work fine and powers on and off with the ignition.
2. (Read below)
3. I believe so. I'm using the included harness in the packaging. I'm not an expert in auto electrics, but it should be a very straight forward installation with this particular amp, as it's a simple thing that goes between the HU and car wiring harness.

The facts:
With the ignition OFF:

• Yellow wire reads 0.67V
• Red wire reads 12.48V
• Green wire reads 8.13V (This wire is the one that connects to the Remote wire on the harness (harness.png)

With the ignition ON:

• Yellow wire reads 12.45V
• Red wire reads 12.42V
• Green wire reads 8.07V

Shouldn't the green wire read 12V? Strange that it's reading 8, right?

Unfortunately I'm in Guernsey so I wouldn't be able to make use of your help in person

 

[Frank Perry]

Interesting - So on the back of the Pioneer HU, you should find a 12V remote cable. This usually only sends the signal when the head unit powers ON. This leads me to thinking the green wire is not the "remote" wire.

Also - the amp you have is not the average amplifier that runs the 3 main connections for power (PWR, GND, REM). Instead, it looks like it has a specific pinout where you should be able to chop & change some of the wires to get it to power ON when the ignition is ON and OFF when ignition is OFF.

The easiest way to achieve the above is to locate the switching wire (remote) directly to the yellow wire. This is your ignition. We need to identify which pin that is on your Pioneer GM-D1004 amp. Check the document for the manual of your amplifier (can be found HERE). Page 6 (section 3) states;

"If the system remote control wire of the amplifier is connected to the power terminal via the ignition switch (12 V DC) the amplifier will remain on with the ignition whether the car stereo is on or off, which may exhaust battery is the engine is at rest or idling."

Most likely the issue you are experiencing here. So - what can you do to rectify this?

Test the amp end using multi-meter on pin 17 (or the blue/white wire) and see if you're getting a 12v reading when the ignition is OFF. Then test the amp end pin 16 (or the yellow wire) to see if this is also showing 12v with the ignition is OFF.

If you can post the results of the above, I should be able to help further

 

[Frank Perry]

Sorry - to make this clearer;



Ignition OFF and test numbers 16 & 17.

 

[Frank Perry]

Also - I just realised the remote cable comes direct from the HU, not your vehicle's wiring....



This is a typical ISO harness for the Pioneer head units - note how the blue/white cable isn't connected to the other plugs - this is the Remote cable that should be connected to Pin 17 (blue/white) on your amplifier...

 

[Brunoandrade98]

Sorry - to make this clearer;

View attachment 154209

Ignition OFF and test numbers 16 & 17.

I haven’t rectified everything you said, just yet, however, correct me if I’m wrong, but the blue and white wire on the Head unit should read:

• 0V when the Head Unit is OFF?
• 12V when the Head Unit is ON?

If so, this is probably where my issue is.
It reads 8.35V whether the Head Unit is ON or OFF.

 

[Frank Perry]

I haven’t rectified everything you said, just yet, however, correct me if I’m wrong, but the blue and white wire on the Head unit should read:

• 0V when the Head Unit is OFF?
• 12V when the Head Unit is ON?

If so, this is probably where my issue is.
It reads 8.35V whether the Head Unit is ON or OFF.

This is indeed your issue. If you pull the bullet connector out - what happens with the AMP then?

 

[Frank Perry]

This blue/white wire needs to be connected to the blue/white wire that comes from the amp (wire number 17 on the below)

 

[Frank Perry]

The comment on this suggests if you are running coax (phono) connectivity for front/rear then it has auto-sensing. Meaning it will turn on/off automatically and usually turns itself OFF when there has been 2 - 3 minutes of no activity.

Have you checked this out?

 

[Brunoandrade98]

This is indeed your issue. If you pull the bullet connector out - what happens with the AMP then?

It wouldn't do anything, as the harness that connects the car wiring to the amp also has one connector coming out of it (best I can explain, see attached), and there are two blue wires on a single one of the pins. One goes to the amp, one goes to the Remote wire on the Head Unit.

If the car is giving me 8V on that wire and I remove the bullet connector, I'm still getting 8V on the blue wire that goes directly to the amp.

Did that make sense?
Please let me know if I should explain better.

I really appreciate your help!
Many thanks

The comment on this suggests if you are running coax (phono) connectivity for front/rear then it has auto-sensing. Meaning it will turn on/off automatically and usually turns itself OFF when there has been 2 - 3 minutes of no activity.

Have you checked this out?

Yup. During my initial stage of troubleshooting, I left it plugged in, locked the car and went off to do my thing for about an hour.
When I came back, it was still on.

 

[Brunoandrade98]

This blue/white wire needs to be connected to the blue/white wire that comes from the amp (wire number 17 on the below)

It gets worse...

I've just had another go and removed the pin that the blue wires connect to on the harness.
After doing this and plugging it to the car, the amp didn't turn on at all.
I guess that was to be expected.

I then measured the voltage on the green wire on the car harness (which the pin with the blue wires I removed earlier would connect to), and it measured 0.6V whether the ignition is ON or OFF...
I left the probes connected to the ground and green wire for a bit and also found that the voltage would vary from 0.6V to 1.6V. (see image "1" and "2")
And that's without touching the ignition...

I then put the pin back in and connected it as I normally would and the amp now doesn't even turn on at all.

In my (rather limited) wisdom, I'd say the green wire and its voltage inconsistency/irregularity is to blame, here.
But what would cause that?

The more I look at this, the worse it gets.

 

[Frank Perry]

It's difficult to help because you're not local - I just want to jump in and unpick this for a few hours to sort it but I'm pretty sh*t at expressing the methodical/logical troubleshooting when it's not in front of me... if you know what I mean? Haha....

My honest opinion at this point... Send the Pioneer amp back (if you can) and get a proper 4ch amplifier and wiring kit. It's much safer, you'll probably get much better sound quality from your speakers and it's so much simpler than the masses of cables that you have at the moment.

Something like the Pioneer GM-D8704 (see the link to Amazon) with a Vibe Wiring Kit (see link again). Connectivity is straight forward although the only small headache is having to run the cables through your car. It'll take a full afternoon to get it in (or perhaps a full day for someone who is a little less experienced) but it's super straight forward.

Naturally amps sit in the boot somewhere - you could mount it to the rear set or something.
Setup as follows;
- Chubby red from battery under bonnet to amp
- Chubby black cable to a seatbelt bolt in the rear (make sure you scrub/sand off paint so it's bare metal)
- Thin Blue cable to the rear of your head unit (the remote cable - alternatively see the below)
- 2 pairs of phono cables that will run from the rear of your head unit to the amp (kit only comes with 1 set so you will need to buy another set see HERE for a set of RCA cables that have a thin cable in the middle that can be used as the blue remote cable, making it neater for installation)

That's the power and audio signal all setup and sent to the amp. Then you need to connect all the speakers directly to the amp;
- Speaker cable from speaker through door panel, hoses and into car. Remove some trims and route all cables through to the amp and simply connect them accordingly.

Once all are connected, you're done. Tune the amp to your discression, HPF or full-range, adjust HPF frequency if using HFP and adjust gain to suit your speaker output and sound levels and you're golden!

 

[Brunoandrade98]

It's difficult to help because you're not local - I just want to jump in and unpick this for a few hours to sort it but I'm pretty sh*t at expressing the methodical/logical troubleshooting when it's not in front of me... if you know what I mean? Haha....

My honest opinion at this point... Send the Pioneer amp back (if you can) and get a proper 4ch amplifier and wiring kit. It's much safer, you'll probably get much better sound quality from your speakers and it's so much simpler than the masses of cables that you have at the moment.

Something like the Pioneer GM-D8704 (see the link to Amazon) with a Vibe Wiring Kit (see link again). Connectivity is straight forward although the only small headache is having to run the cables through your car. It'll take a full afternoon to get it in (or perhaps a full day for someone who is a little less experienced) but it's super straight forward.

Naturally amps sit in the boot somewhere - you could mount it to the rear set or something.
Setup as follows;
- Chubby red from battery under bonnet to amp
- Chubby black cable to a seatbelt bolt in the rear (make sure you scrub/sand off paint so it's bare metal)
- Thin Blue cable to the rear of your head unit (the remote cable - alternatively see the below)
- 2 pairs of phono cables that will run from the rear of your head unit to the amp (kit only comes with 1 set so you will need to buy another set see HERE for a set of RCA cables that have a thin cable in the middle that can be used as the blue remote cable, making it neater for installation)

That's the power and audio signal all setup and sent to the amp. Then you need to connect all the speakers directly to the amp;
- Speaker cable from speaker through door panel, hoses and into car. Remove some trims and route all cables through to the amp and simply connect them accordingly.

Once all are connected, you're done. Tune the amp to your discression, HPF or full-range, adjust HPF frequency if using HFP and adjust gain to suit your speaker output and sound levels and you're golden!

Thank you for this.

It sounds like I'd have a lot of fun doing this, but all my budget allows (for now), is to use what I already have, as I still need to buy new component speakers for the front (open to suggestions, by the way).

Not to mention that the sound quality difference might not be noticeable for my untrained ear. I'd love to hear the differences, though, so, I might do some research.

With that said, for now, I'm going to try and tackle the issue with the voltage irregularity, which is probably something I shouldn't just ignore.

I have got my hands on wiring diagrams but quite frankly, they're quite hard to navigate through, so, I'm never really too sure what I'm looking at.
I'll probably make another post soon, to see if anyone has any ideas, now that I know what the actual issue is.

Many thanks