Aftermarket Head Unit Rapidly Draining Battery?

[oguruma]

Hello, I have a 2006 F 250 Superduty (5.4L V8). I removed the factory head unit (AM/FM only) and put in a Pyle Aftermarket CD Player. I used an aftermarket harness soldered to the harness that came with the new Head Unit. All connections seemed like they are soldered well.

After I connected the aftermarket head unit, it turned on well and worked fine. After listening to the CD player with the engine NOT running, I found that the battery was dead between 5-10 minutes. I recharged the battery and it held a charge just fine. I tested the system for parasitic draw with a DMM, and it registered a 10 mA draw with everything turned off and the CD player unplugged. So there obviously isn't a draw that is killing the battery.

This leads me to believe that it is the new head unit and a short somewhere. However, the CD player works just fine (until the battery dies).

Any ideas?

 

[michaelluscher]

You did remember to hook it up to a SWITCHED power source, correct?

 

[oguruma]

Its connected to the factory radio wiring....

 

[Mr Nice]

How old is your battery?

 

[horse123]

You shorted something, even playing a 20 speaker system with 5kW of power on a run of the mill battery would not drain it in 10 minutes or less.

 

[eljefino]

Even through a 50 amp fuse the battery wouldn't die in ten minutes. I, too, wonder what's up.

Try running your headlights for ten minutes to see if that kills it?

 

[oguruma]

I'm not sure how old the battery is. I can't find any sticker that indicates the date of manufacture. It is the OEM battery, so it is possible that it's the original battery from 2006, but I can only speculate.

 

[Olas]

Plug the head unit in and check for draw just to be sure, check your solder and check the pin out's against the loom

 

[oguruma]

I might have screwed up my DMM, since it's not fused, but I connected the factory harness and it read as over 10 Amps with the doors shut and everything else off. It went back down to 10 mA when I unplugged the harness. Would this indicate that there is a short in the harness?

 

[HerrStig]

A short is a close to zero ohm connection. Shorts blow fuses and melt wiring. Anything drawing 10 amps is consuming over 100 watts of power and THAT should show up somewhere as heat or the ignition system being on or a fuel pump runnning or lights on. running or the like. You can't bury 100 + watts in a car without it showing up somewhere. However even 100 watts will not kill a battery right away. Most car batteries will product 70 amps or so for an hour when new or 35 amps for two hours, and so on. You need to be sure your meter is reading right and look at the main power lead going into the head unit for current. Also, many systems these days have external amps driven by the stock head unit. They may be waiting for an "off" signal the aftermarket unit doesn't provide. You might have to hit a good car stereo shop for this problem. THere's something called a "Can Bus" in post 2000 cars and it doesn't use point to point wiring, but rather sends signals on the +12 lead with turn on and turn off info.

 

[OneEyeJack]

Unplug the CD unit and start trouble shooting.

 

[Rand]

maybe the Radio itself is bad?

Its called "PYLE" for a reason. Pyle of poop.

 

[asand1]

Originally Posted By: oguruma


After listening to the CD player with the engine NOT running, I found that the battery was dead between 5-10 minutes. I recharged the battery and it held a charge just fine. I tested the system for parasitic draw with a DMM, and it registered a 10 mA draw with everything turned off and the CD player unplugged.


Have you plugged the CD player in and turned it off to see it the battery would hold? How many watts is the CD rated at?

Did you cut your stock harness or use the adapter pigtail?

 

[oguruma]

I used an aftermarket pigtail adapter. The battery dies with just the aftermarket adapter plugged in and nothing on

 

[eljefino]

Did you do anything with the (typically) blue wire, the one that powers other stuff? It should be capped off unless you have an amp, power antenna, etc.

Funny story, I miswired my saturn once as there were two orange wires, one went to the parking lights but I wired it as a speaker. Yup, the lights flashed to the beat. Funny but I un-did it.

 

[oguruma]

I taped off the un-used wires...

 

[Rand]

I'm at a loss for your issue. if you short something you are melting wiring or a fuse.. and if that doesnt happen not sure how it could drain that fast.

 

[oguruma]

I am at a loss as well... There are definitely no melted wires... The battery holds a charge just fine as long as the harness is not plugged in. If that harness is plugged in the battery dies. This is even if the radio isn't plugged into the aftermarket harness....

 

[Jimmy9190]

Does the harness for the Pyle deck have plastic boxes inline on either the red accessory power wire or the yellow constant power wire? If so, the boxes contain noise filtering circuits. Some aftermarket decks have the filters inline to suppress noise from the engine and/or alternator. It is possible the noise filters could have a bad resistor or toroid choke or just be wired incorrectly. If you do have the inline filters, cut them off and reconnect the wires, plug in the harness without connecting the deck and see if the problem persists.

 

[oguruma]

There is no in-line filter, just a fuse on the constant wire. I am kind of afraid to keep trying things at this point, for fear of killing this lead-acid battery too many times...