Parasitic Draw

[ramchol76]

My ppv has a parasitic draw of around 2.5 amps, checked main fuse block and dash fuse block. none there causing the draw.

I notice my PPV has atleast 5 wires getting out of positive battery terminal. I think some might be related to police accessories which are removed and may not be passing through the fuse blocks. is there a way I can identify and remove such police accessory related wires which are no more used.

 

[1BADI5]

Oh boy, that's a loaded question.

You can either go through the process of testing all of the circuits........blah

I would start by chasing those 5 leads you speak of and see where they go or teminate. If they're unneeded or used, remove them from the battery. I'd remove all 5 from the battery from the get go and test, then work from there.

I swear everytime I work on my PPV I pull 10 more feet of unused cable/wiring out of the truck; at this point I have pulled nearly 100ft or 7 lbs of unneeded wiring/coax cable.

 

[OR VietVet]

The first thing I do when I check for a draw is disconnect the alternator with the DVOM attached. Then trace down those wires.

 

[ramchol76]

Oh boy, that's a loaded question.

You can either go through the process of testing all of the circuits........blah

I would start by chasing those 5 leads you speak of and see where they go or teminate. If they're unneeded or used, remove them from the battery. I'd remove all 5 from the battery from the get go and test, then work from there.

I swear everytime I work on my PPV I pull 10 more feet of unused cable/wiring out of the truck; at this point I have pulled nearly 100ft or 7 lbs of unneeded wiring/coax cable.

agree, I am reading the wiring diagram. I will be removing some of this.

 

[ramchol76]

The first thing I do when I check for a draw is disconnect the alternator with the DVOM attached. Then trace down those wires.

can you please explain more, does the disconnecting alternator helps better troubleshoot?

 

[OR VietVet]

can you please explain more, does the disconnecting alternator helps better troubleshoot?

The internal diodes in the alternator are well known as sometimes going bad and causing a draw. Just unplug the alternator, when you see the draw on your DVOM, and if it goes away, the alternator should be replaced. Many other things can cause a draw but the alternator test is simple and fast. If unplugging the alternator does not stop the draw, then you start looking elsewhere and unplugging other items and pulling fuses till you find the culprit circuit.

 

[ramchol76]

The internal diodes in the alternator are well known as sometimes going bad and causing a draw. Just unplug the alternator, when you see the draw on your DVOM, and if it goes away, the alternator should be replaced. Many other things can cause a draw but the alternator test is simple and fast. If unplugging the alternator does not stop the draw, then you start looking elsewhere and unplugging other items and pulling fuses till you find the culprit circuit.

Will try this!

 

[Fless]

Are the NNBS dash clusters prone to do this like the NBS clusters do? Seems like the right amperage for the silver migration issue....

 

[ramchol76]

tested today, alternator is good (not drawing) and the draw is from the wire heading to under hood fuse box. I think I need to check the 3rd fuse box left to steering column.

can someone help identify what is the last wire (in attached pic) heading to?

thanks

 

[bladenbullet]

are you waiting long enough for all the modules to go to sleep before determining parasytic draw?...and you should not disconnect the battery until the meter is attached so there is no interruption in power...a digital voltmeter across fuse terminals will show a voltage drop if a circuit is alive and drawing...if a circuit is dead it will show no drop...