Amp turn on/parasitic drain

[Superspirit]

I have installed aftermarket amps and have a parasitic drain. I believe the bcm fusebox is not allowing the truck to go to sleep. With the add a fuse installed. When I checked for switched ignition all the locations recommended on this forum will have 13 volts key on and fluctuate to 7 volts and back to 13 back and forth with key off. Guessing it's the bcm can circuit. Anyway i can close all the doors and leave a window down and the back seat forward and watch my amp light turn on and off. This is killing batteries. I thought I was just having bad luck with batteries but have upgraded to a new lariat battery 2 weeks ago and I'm already back to getting the low battery message when I enter the truck after 1 day of sitting. So with all that info where can I pick up an amp turn on signal that won't trigger the bcm wake circuit? 22 Ranger XLT 4X4

Edit to add the turn on signsl ignites 3 devices, a dsp, a 4ch interior amp snd a sub amp. All of which have power indicator lamps that I believe are the trigger of the wake up signals to the bcm.

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[RangerBill]

I have installed aftermarket amps and have a parasitic drain. I believe the bcm fusebox is not allowing the truck to go to sleep. With the add a fuse installed. When I checked for switched ignition all the locations recommended on this forum will have 13 volts key on and fluctuate to 7 volts and back to 13 back and forth with key off. Guessing it's the bcm can circuit. Anyway i can close all the doors and leave a window down and the back seat forward and watch my amp light turn on and off. This is killing batteries. I thought I was just having bad luck with batteries but have upgraded to a new lariat battery 2 weeks ago and I'm already back to getting the low battery message when I enter the truck after 1 day of sitting. So with all that info where can I pick up an amp turn on signal that won't trigger the bcm wake circuit? 22 Ranger XLT 4X4

Edit to add the turn on signsl ignites 3 devices, a dsp, a 4ch interior amp snd a sub amp. All of which have power indicator lamps that I believe are the trigger of the wake up signals to the bcm.

Where did you tap into for your amp turn-on signal? If you disconnect it, is everything normal?

 

[airline tech]

As Ranger Bill asked - where are you tapped? plus what trim do you have - The B&O or non-B&0?

 

[JerryRange]

Try tapping into the radio's switched power wire instead of using an add-a-fuse in the BCM - that should give you a clean turn-on signal without triggering the wake circuit.

 

[Superspirit]

As Ranger Bill asked - where are you tapped? plus what trim do you have - The B&O or non-B&0?

@airline tech ,@RangerBill , I have tapped fuse 35, and 37. I have xlt without branded oudio. 301A package. It's in 35 for branded audio but still doing that. According to my owners manual it's not used.

 

[Superspirit]

Try tapping into the radio's switched power wire instead of using an add-a-fuse in the BCM - that should give you a clean turn-on signal without triggering the wake circuit.

I have considered doing that. Just don't want to take the dash apart and open T harness again.

 

[RangerBill]

@airline tech ,@RangerBill , I have tapped fuse 35, and 37. I have xlt without branded oudio. 301A package. It's in 35 for branded audio but still doing that. According to my owners manual it's not used.

If you disconnect that wire to fuse 35 (in the BCM?) does the drain go away? Fuse 35 in the BCM should be ok, as it is fed by a relay. Perhaps your main power feed to the audio amp (not at F35) is back feeding voltage to F35 when the ignition is off.

 

[airline tech]

To CONFIRM - The fuse tap is only for the (Remote Turn On) correct? and you are powered separately?

The remote turn on does not take much current (about 5 to 20mA) to trigger the turn on and the BCM does not see enough load change at key off - to shut the circuit down and it keeps it alive.

I would have to dig some for an alternative solution, if the amp supports it - use a speaker wire (audio signal) as the trigger comes to mind - It's been a while since i dealt with audio upgrades

 

[Superspirit]

The amp power source is a 4 ga from battery. 1 to each amp the turn on is only for amp and dsp turn on. Dsp pulls power from radio power in t harness. To insure test procedure all supposed switched fuses in bcm fuse box have the same voltages key on key off as listed in the original post when tested with a dvm. I wanted to add they will turn a test light bright and dim as the voltage fluctuate. With key off. I have not been able to find a point inside the cab that will go on and off with the key when testing with an old fashioned test light

 

[airline tech]

You are highlighting something here that - I need to dig deeper into and that is the BCM control of power from the interior fuse box.
The Factors

1. Testing with the door open - try latching the door lock, closed to simulate the door being closed.
This I believe may be part of the reason you are seeing the results you are getting

2. Key off - Accy Delay Power - this is also affecting your test results,
How Long does the AMP stay powered - 10 Minutes? or no shut-off at all?

3. Actual Load of the power on a FET monitored circuit

4. Alot of the modules are always powered and use the (ISP-R) signal to turn them on such as the ACM and FCIM

I will have to dig deeper into this to gain a better understanding on what is happening

 

[RangerBill]

The amp power source is a 4 ga from battery. 1 to each amp the turn on is only for amp and dsp turn on. Dsp pulls power from radio power in t harness. To insure test procedure all supposed switched fuses in bcm fuse box have the same voltages key on key off as listed in the original post when tested with a dvm. I wanted to add they will turn a test light bright and dim as the voltage fluctuate. With key off. I have not been able to find a point inside the cab that will go on and off with the key when testing with an old fashioned test light

Try removing your tap on fuse 35 and test again for voltage at Fuse 35 in the BCM when the ignition is off. If there is no voltage with your wiretap disconnected, then the amp is backfeeding voltage through the ignition sense wire that you disconnected.

 

[Superspirit]

Try removing your tap on fuse 35 and test again for voltage at Fuse 35 in the BCM when the ignition is off. If there is no voltage with your wiretap disconnected, then the amp is backfeeding voltage through the ignition sense wire that you disconnected.

That voltage was before the ammo was ever installed. Got that checking before I ever installed.

 

[Superspirit]

You are highlighting something here that - I need to dig deeper into and that is the BCM control of power from the interior fuse box.
The Factors

1. Testing with the door open - try latching the door lock, closed to simulate the door being closed.
This I believe may be part of the reason you are seeing the results you are getting

2. Key off - Accy Delay Power - this is also affecting your test results,
How Long does the AMP stay powered - 10 Minutes? or no shut-off at all?

3. Actual Load of the power on a FET monitored circuit

4. Alot of the modules are always powered and use the (ISP-R) signal to turn them on such as the ACM and FCIM

I will have to dig deeper into this to gain a better understanding on what is happening

To answer #2 the amp continually starts and stops. With the window down and all doors closed and the back of the rear seat forward to see the amp and the indicator light. The amp will come on then go off, a few seconds later maybe a minute it will do it again. This afternoon I was reformatting the sd card in my dash cam. While setting in the truck doors closed I could hear the subwoofer fire up with a thump and then go off, every minute or so. It's recieving enough voltage to ignite but then it shuts down. This matches what I see with a dvom and test light. This never shuts down unless it does it after the 2hr power point timeout.

 

[RangerBill]

That voltage was before the ammo was ever installed. Got that checking before I ever installed.

Was the battery draining before the amp was installed?

 

[Superspirit]

I'm thinking it was. But not as bad as now. As the truck is 45mos old and is now on the 3rd battery. At 2 years dealer replaced battery for the same warnings when entering the truck. Then about 3 months ago i started getting the warning again. I had the dealer test the battery and they said it was low and charged it but no warranty since it was already a replacement. then after the amp install it started giving the warning again so I went to Sams and had the battery tested again it passed first test but failed after charging. So I replaced the battery with the bigger lariat battery. And 2 weeks later. Here we are. Warning again.

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