Aftermarket Head Unit Rapidly Draining Battery?

[The_Eric]

I think we're missing some info from you.

What is the amperage draw with the radio hooked up? What about with the radio on?

When you were listening to the radio after you hooked it up, did you have the key in the "ON" position or the "ACCY" position? If you were listening to the radio with the key in "ON" and the battery is the original, it very well could have drained it in 5-10 minutes and still restarted the truck after charging- then appear normal.

I'd be surprised that there is a problem with the new radio and if there is, you should be able to figure it out pretty easily. Most have spindly little power and memory wires. If it's drawing enough to drain a battery in 5-10 minutes, they are going to be HOT, or the fuse (which is typically less than 5 amps) will blow.

 

[meep]

1. no radio should kill a battery in ten minutes

2. no radio should pull 10 amps off

3. for a radio to pull 10 amps on, it would have to be up very loud (by normal standards).

4. possible the switched output drives external loads, factory amp, etc..

Sounds to me like:
1. the radio is faulty

2. the wiring harness is cross between memory power and radio power. see if the display turns off when the ignition key is removed. it should.

 

[dishdude]

Originally Posted By: meep
1. no radio should kill a battery in ten minutes

2. no radio should pull 10 amps off

3. for a radio to pull 10 amps on, it would have to be up very loud (by normal standards).

4. possible the switched output drives external loads, factory amp, etc..

Sounds to me like:
1. the radio is faulty

2. the wiring harness is cross between memory power and radio power. see if the display turns off when the ignition key is removed. it should.


Agreed, if something is sucking that much juice, it's got to be getting HOT!

 

[HangFire]

Originally Posted By: michaelluscher
You did remember to hook it up to a SWITCHED power source, correct?

Originally Posted By: oguruma
Its connected to the factory radio wiring....


You may think you've answered his question, but you have not. Factory wiring can contain both switched and unswitched power.

 

[asand1]

Were you following directions and looking at wiring diagrams when connecting, or did you just try matchng colors. If its drawing over 10 amps with just the harness adapter plugged in, and the deck unplugged, then you did it wrong.

 

[oguruma]

Originally Posted By: HangFire
Originally Posted By: michaelluscher
You did remember to hook it up to a SWITCHED power source, correct?

Originally Posted By: oguruma
Its connected to the factory radio wiring....


You may think you've answered his question, but you have not. Factory wiring can contain both switched and unswitched power.


I am not sure what you mean by switched and unstitched power.... There is a wire that will light up a test light whether the key is on the ACC position or not. There is a red wire that will light up the test light only when the key is on the ACC/Run position. The head unit turns on/off accordingly, just like the factory radio. The factory wiring diagram matches the wiring for the head unit and aftermarket pigtail adapter.

What blows my mind is how the truck will hold a charge all night when the pigtail is not plugged in, but it can't hold a charge for 30 minutes with the adapter plugged in....

 

[Olas]

The pigtail is the problem - I'm gonna guess at the one of the +ve feeds is shorting against an earth

 

[The_Eric]

Originally Posted By: oguruma


What blows my mind is how the truck will hold a charge all night when the pigtail is not plugged in, but it can't hold a charge for 30 minutes with the adapter plugged in....


How many times have you drained the battery with the harness plugged in?

 

[HangFire]

Originally Posted By: oguruma

I am not sure what you mean by switched and unstitched power.... There is a wire that will light up a test light whether the key is on the ACC position or not.


That is unswitched power. It stays on all the time.

Originally Posted By: oguruma
There is a red wire that will light up the test light only when the key is on the ACC/Run position.


That is the switched power.


Originally Posted By: oguruma

The head unit turns on/off accordingly, just like the factory radio. The factory wiring diagram matches the wiring for the head unit and aftermarket pigtail adapter.

What blows my mind is how the truck will hold a charge all night when the pigtail is not plugged in, but it can't hold a charge for 30 minutes with the adapter plugged in....


That last bit should make it easy to track down. The pigtail has a short to ground, or facilitates a short to ground through the Pyle. For example connecting unswitched power to the Pyle's Ground lead, and then bolting the Pyle's metal chassis to the vehicle's metal, could provide a path from power to ground that will drain your battery.

 

[asand1]

Originally Posted By: HangFire
That last bit should make it easy to track down. The pigtail has a short to ground, or facilitates a short to ground through the Pyle. For example connecting unswitched power to the Pyle's Ground lead, and then bolting the Pyle's metal chassis to the vehicle's metal, could provide a path from power to ground that will drain your battery.


Except the pigtail adapter does it without the stereo being plugged in. I suspect 12v is being sent to a speaker through the pigtail abapter..

Do you hear a speaker pop when plugging in the adapter?

 

[HerrStig]

Originally Posted By: asand1
Originally Posted By: HangFire
That last bit should make it easy to track down. The pigtail has a short to ground, or facilitates a short to ground through the Pyle. For example connecting unswitched power to the Pyle's Ground lead, and then bolting the Pyle's metal chassis to the vehicle's metal, could provide a path from power to ground that will drain your battery.


Except the pigtail adapter does it without the stereo being plugged in. I suspect 12v is being sent to a speaker through the pigtail abapter..

Do you hear a speaker pop when plugging in the adapter?
That's a good question for him. Might lead him to a factory amp drawing current but tucked away in a place where the heat generated is not easy to notice. I'd look for a reference in the vehicle manual for an external amplifier supply fuse, it's not going to be on the head unit power leads.
Pull that and see what happens, or measure current draw through that fuse holder. External amps are generally biased to draw little current when not being driven.

 

[HerrStig]

BTW is there more than one wire running to the battery plus terminal?

 

[asand1]

Originally Posted By: HerrStig
That's a good question for him. Might lead him to a factory amp drawing current but tucked away in a place where the heat generated is not easy to notice.


Not likely, considering it was just an AM/FM radio. Maybe if it was a Monsoon/Bose/etc system