Author Topic: Trying to Pinpoint my Parasitic Draw  (Read 1811 times)

Offline Eddie86

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Trying to Pinpoint my Parasitic Draw
« on: March 10, 2019, 03:45:07 PM »
I've been having issues with my new battery (which I know is good) draining after sitting a few days on my 1986 Silverado K10. I have just recently replaced the alternator, battery, starter solenoid and many wires and fuseable links going to the starter. Also checked, replaced/repaired and cleaned all of my ground connections and have new battery cables. After recharging the battery, I did a parasitic draw test with a test light inline with my negative cable and started pulling fuses. I started with unplugging (replaced that plug too) the new alternator and the test light did not go out. It wasn't until the last pull of the metal 30amp fuse for the "PWR ACC" that the test light finally went out. The truck has power windows and power locks. Before removing the fuse, I know the one window switch on the driver door was working in reverse (button up made window go down and vice versa). Both windows did operate and the door locks operated.

Questions:

1. Can anything more be on that circuit that I'm missing?
2. Does the fact that the one window switch is working in reverse have anything to do with the draw?
3. If the window or door lock was causing the draw and I know they were operating, why wasn't I seeing the windows moving or hearing the door lock activate continuously?
4. If those are the only two things on the "PWR ACC" circuit, would it have to be the door lock since the windows would only work with the key in the run position?   

Have not pulled the door panels yet, That's probably next weekend. would just like to have an idea of where to start looking/testing when I do.

Thanks!
Ed

Offline bd

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Re: Trying to Pinpoint my Parasitic Draw
« Reply #1 on: March 10, 2019, 06:41:42 PM »
Any circuits plugged into the three PWR cavities of the fuse box are powered off of that 30-amp circuit breaker.  The power door locks should be an orange wire with a black stripe (org/blk).  Reinstall the C/B and check your test light.  Then unplug the org/blk wire from the PWR cavity and check the test light again.  If the test light extinguishes after the org/blk wire is disconnected then the parasitic draw is coming from the power door lock circuit.  Substitute an ammeter for the test light and determine just how much of a draw actually exists.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Eddie86

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Re: Trying to Pinpoint my Parasitic Draw
« Reply #2 on: March 10, 2019, 08:39:39 PM »
Awesome! Thank you BD. I will check that. Hopefully sometime this week. I'll report what I find.

Any thoughts on the reverse function of that window switch? Is it possible to install the switch into that holder upside down?

Offline bd

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Re: Trying to Pinpoint my Parasitic Draw
« Reply #3 on: March 10, 2019, 11:00:16 PM »
Any thoughts on the reverse function of that window switch? Is it possible to install the switch into that holder upside down?

More than likely, that's what happened.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline roundhouse

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Re: Trying to Pinpoint my Parasitic Draw
« Reply #4 on: March 11, 2019, 07:10:07 PM »
I had one vehicle that it was the radio draining the battery

Not sure why since the radio worked fine
But after I tracked it down and unplugged it
The battery would no longer go dead