[Lexifer]

When my car is off it has a drain on the battery that I think is coming from my alternator that might have a short.

I bought a multimeter. How do I use it to check the alternator if it is drawing power from the battery? Where do I put the red and black contacts and what settings do I put it on. I'm clueless. Thanks.

 

[VP500]

The alternator can't really drain power. They produce the power.

Take the car to auto zone or some place that does alt tests for free and they will tell you what's going on.

 

[Lexifer]

Thx VP,

I was actually doing some research and if you have a bad diode or short in your alternator it will drain your battery while it is off. Its called a parasitic drain. Normally when the car is off the alternator shouldn't draw any power from the battery. Thats is what I want to test for, but I don't know where to put the leads from the digital multimeter. If I get a reading than I know my alternator is bad, if I don't get a reading than I know my alternator is fine.

I STILL NEED HELP!

 

[ItalynStylion]

Disconnect the alternator and see if the drainage while the car off still persists.... simple solution

 

[Lexifer]

ItalynStylin,

How do I disconnect the alternator? I can see it and I see 2 cable plugged into it. 1 higher and than 1 below that. Do I just pull them out, I tryed and they aren't coming out. Is the a pinch around the edge of the connector I have to squeeze to pull it out and which one should I pull out, upper or lower cable? Thx

 

[lyk]

theres 1 wire that goes up from the bottom of the car to the top of the battery.. it rides along the right side of the battery. theres a screw that holds the wire onto the battery along with the other wires... just unhook that wire..

 

[Lexifer]

the wire that goes to the bottom of the car goes to a fuse box and the alternator so if I do that i'm not testing the alternator alone, i'm testing the alternator and all the circuits in the fuse box.

My drain was 0.35 amps. Normal drain is .05-.06 amps when the car is off.

I decided to just test each circuit, I chose my radio circuit fuse first because I got a deck installed about 6 months ago. AND GUESS WHAT!!!!

after I pulled my radio circuit fuse my drain went back to normal, .06 amps!

Does anybody know of any reasons why my deck might be drawing energy while the car is turned off? And what else is connected to the radio circuit besides the radio that might be causing the problem?

 

[lyk]

every time you give power to the stereo HU after taking it power away, the HU checks for cds in each slot. That's the only thing I can think of with the car off.

 

[ItalynStylion]

the wire that goes to the bottom of the car goes to a fuse box and the alternator so if I do that i'm not testing the alternator alone, i'm testing the alternator and all the circuits in the fuse box.

My drain was 0.35 amps. Normal drain is .05-.06 amps when the car is off.

I decided to just test each circuit, I chose my radio circuit fuse first because I got a deck installed about 6 months ago. AND GUESS WHAT!!!!

after I pulled my radio circuit fuse my drain went back to normal, .06 amps!

Does anybody know of any reasons why my deck might be drawing energy while the car is turned off? And what else is connected to the radio circuit besides the radio that might be causing the problem?

Maybe you mixed up the ignition and the power wires?

Let me ask you...can you turn the radio on when the car is off with no key in the ignition?

 

[Lexifer]

haha nah I can't turn the radio on when the car is off and their is no key in the ignition.

ok I narrowed the power drain down to a circuit board. In order to keep my stock navigation I had to remove a circuit board from my stock stereo and keep it plugged in some how. So I removed the circuit board from the stock stereo and plugged the original harness into it, secured it under my passengers side foot panel. Well it just keeps drawing energy and I don't know why? Does it need to be grounded, if so where the hell do I ground a circuit board? I'm lost.

Here's a pic of the circuit board. How can I stop it from drawing power when the car is off. This is going to be tough...

 

[lyk]

lmao!!
I hope you find out before I do the same thing.
I have actually been having trouble figuring out how you guys did that.. did you just tap into 3 of the wires and have those plugged into the circuit board?


you live so close to me.. you should just do it for me so I can get an aftermarket deck already =)

 

[lyk]

wait... did you actually unplug it and check to see whether or not your battery is still being drained?


I can't remember if there are two harnesses going into the stock HU for people who have navi too... so if you could answer that for me thta would be gggreat

 

[Lexifer]

Yea I put my radio fuse back in and I got a draw of .36 amps I than thought about the circuit board and unplugged the wire harness to it and viola and draw dropped to .06 amps

Its been awhile and yea I think it had 2 wire harness's going into the stock HU. I plugged this one in because it was the larger of the 2 and the navi worked so I thought I was done. It wasn't until I went on vacation for 2 weeks and came home to a dead battery twice that I decided to start looking into it. Tomorrow morning I think I'm going to check all my wiring again and possibly try to plugged that 2nd harness in and than check the battery draw. Its too late now i'm tired... I'll let you know what happens, but i'm still open to suggestions from anyone.

Removing the circuit board is actually very easy and I think its really worth it, or else you lose factory NAV.