So we finally found the source of the parastic battery drain. It's the Pioneer AVIC8400 stereo head unit. But why it's happening is still a mystery. The drain is about 2amps. By removing fuses we found about half is from the head unit and the remainder is from the Bose amp. The kicker is that it is cyclable. The drain isn't there when the car ignition is first turned off and the radio powers down. But after a while (not sure exaclty how long) something triggers the radio and thru the radio, the amp, to start pulling power. Has anyone run into this before. Any suggestions? Is the radio head unit bad? Or could it be Maybe a sleep setting? Could it have anything to do with the aftermarket backup camera? Maybe a bad harness? Stereo and backup camera were installed by a reputable car stereo shop. Thanks
Fix For Head Unit Receiver causing Parasitic drain?
- Thread starter m1949
- Start date
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nonickatall
Full Access Member
Normally the head unit receives power via ignition plus, switches on the radio when the ignition is switched on and via permanent plus to maintain the settings for radio stations, for example.
So you have to measure whether something is happening on the ignition plus that turns on the main unit, otherwise it is the head unit that is causing the error.
I don't think it has anything to do with the aftermarket camera, as the aftermarket camera is only activated via an output on the head unit which is triggered by an input where you connect the plus from the reverse light or switch and you have the signal line from the camera that transmits the image.
The amplifier, on the other hand, is switched on directly via a cable from the radio when the head unit detects ignition plus.
So I would switch off the car and measure on the ignition plus input on the head unit if they are occurs a voltage after a while which would switch on the head unit. Fortest purposes you can as well at a switch in this line where you can switch on the radio manually.
If there is no voltage coming after you switch of ignition your problem must be in the head unit itself.
So you have to measure whether something is happening on the ignition plus that turns on the main unit, otherwise it is the head unit that is causing the error.
I don't think it has anything to do with the aftermarket camera, as the aftermarket camera is only activated via an output on the head unit which is triggered by an input where you connect the plus from the reverse light or switch and you have the signal line from the camera that transmits the image.
The amplifier, on the other hand, is switched on directly via a cable from the radio when the head unit detects ignition plus.
So I would switch off the car and measure on the ignition plus input on the head unit if they are occurs a voltage after a while which would switch on the head unit. Fortest purposes you can as well at a switch in this line where you can switch on the radio manually.
If there is no voltage coming after you switch of ignition your problem must be in the head unit itself.
Does the fact the radio shuts down correctly when ignition is turned off and the drain doesn’t begin for a while after its off mean the problem is more likely in the head unit? People who installed it think the “sleep mode” logic in the head unit my be malfunctioning.
Can you point us to the description of the "sleep mode" logic that is supposedly in the HU? Your truck has RAP and that should turn off the main power to the HU.
Unless there's some non-standard wiring happening.
Unless there's some non-standard wiring happening.
nonickatall
Full Access Member
Has the problem of parasitic discharge existed since the radio was installed or did the problem only arise at some point?
The radio was installed in 2021. I didn't notice a problem until about a month ago.
nonickatall
Full Access Member
Then it might not be a faulty installation, but rather that the radio is defective. I would make an ignition plus switch before the unit and see what happens when you turn it off. If the battery still drains, it's definitely the radio.
Thank you all for the suggestions. I took it to the shop which previously worked on the radio. They found a bad relay in the aftermarket harness was intermittently arming and producing the drain.
SilverSport
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glad you found and resolved your issue with your Escalade and for getting back here to report the cause and fix...enjoy the ride!
Bill
Bill
Sackett2622
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I had the same problem with a Bose sound system in my Tahoe. We unhooked both battery cables from the battery for 24 hours and it was fine after we hooked them back up the next day. The problem was the Body Control Module mistakenly thought it needed to stay “awake” to provide power to the head unit Even when the vehicle was off and not running, thereby draining the battery overnight. By unhooking the two battery cables for about 24 hours, the BCM reset itself. The other option if that does not help, is to either take it to a mechanic and have the BCM reflashed, or replaced. Reflash = about 200.00, Replace = whatever the shop feels like charging. I would try unhooking the cables first. Good luck.
