Posts : 4560 Join date : 2009-08-01 Age : 59 Location : Sanford, NC
Subject: Amperage draw when off? LT1 car. Sun Apr 20, 2014 1:51 pm
So what should the Amp draw be on a "resting" car. If I unplug the underhood light I get about .03 amps. Seems reasonable for the clock and PCM.
back story: I was trying to find an issue. My battery died the other day for no apparent reason, charged it and it did it again. Had the battery tested (Optima) on the car and it was fine. So I took it down separately to a different shop and it still tested good. Put a multimeter between the negative terminal and a ground with the negative battery terminal unhooked from the car and began to pull fuses. No results from that. Not sure if I cleaned up a corroded wire in my messing around or what.
lakeffect
Posts : 3892 Join date : 2009-08-18 Location : Rochester NY 14621
Subject: Re: Amperage draw when off? LT1 car. Sun Apr 20, 2014 9:02 pm
When you pulled fuses, at what point did the draw diminish (or stop)
My story relates to replacing batteries and alternators, only to find out on a very cold day that the rear window defroster was never turning off, and draining the battery. Found out when I went outside, the car was covered with frost and the wear window steaming. Nnever went back to the shop selling me batteries and alternators.
So as I'm sure you are already in search of it, if you can find the circuit that is draining via a large amp draw, it should help you isolate the cause.
BigBlackBeaSSt
Posts : 4560 Join date : 2009-08-01 Age : 59 Location : Sanford, NC
Subject: Re: Amperage draw when off? LT1 car. Sun Apr 20, 2014 9:16 pm
Looking for the definition of large.
95BRMW
Posts : 1695 Join date : 2009-08-15 Age : 40 Location : Connecticut
Subject: Re: Amperage draw when off? LT1 car. Sun Apr 20, 2014 9:20 pm
The Buick knowhow video has a different way of testing the draw. They put a cut off switch between the battery and negtive cable, and also did the meter in parallel with that as you did. They then started the car, let it idle and shut it down, then disconnect the negative cable using the cut off switch. The idea is to "wake up" all the electronics as the draw might not show by just hooking up the cable.
lakeffect
Posts : 3892 Join date : 2009-08-18 Location : Rochester NY 14621
Subject: Re: Amperage draw when off? LT1 car. Sun Apr 20, 2014 10:15 pm
Can you post a link to the video for us?
Best regards, Dave
95BRMW
Posts : 1695 Join date : 2009-08-15 Age : 40 Location : Connecticut
Subject: Re: Amperage draw when off? LT1 car. Mon Apr 21, 2014 8:05 am
Skip to about 11:30 for parasitic draws.
lakeffect
Posts : 3892 Join date : 2009-08-18 Location : Rochester NY 14621
Subject: Re: Amperage draw when off? LT1 car. Mon Apr 21, 2014 8:13 am
Aught to make that video into a sticky.
BigBlackBeaSSt
Posts : 4560 Join date : 2009-08-01 Age : 59 Location : Sanford, NC
Subject: Re: Amperage draw when off? LT1 car. Mon Apr 21, 2014 9:39 am
STICKY!!!!!
DBeaSSt Admin
Posts : 2585 Join date : 2008-11-04 Age : 54 Location : Front Royal, VA
Subject: Re: Amperage draw when off? LT1 car. Mon Apr 21, 2014 10:24 am
Nice resource, thanks Dave!
and sticky-ed!
95BRMW
Posts : 1695 Join date : 2009-08-15 Age : 40 Location : Connecticut
So my parasitic draw continues to this day!!! I was finally able to find the source last night. I used an amp clamp. I had 1.6 amps of draw when the battery was at 6 volts last night. Began pulling fuses one at a time. When I pulled the antenna fuse it all went away. Not sure if it is the antenna, the relay or the radio. Attempted to do further troubleshooting this evening, but after I charged the battery the draw is gone!!!
Andebe
Posts : 3323 Join date : 2013-02-20 Age : 55 Location : Centerville, IN
Subject: Re: Amperage draw when off? LT1 car. Thu Sep 07, 2017 9:55 am
Did you yell,"FINALLY"?
BigBlackBeaSSt
Posts : 4560 Join date : 2009-08-01 Age : 59 Location : Sanford, NC
Subject: Re: Amperage draw when off? LT1 car. Thu Sep 07, 2017 10:07 am
No! It's Intermittent so NOW I cannot test further!