Chasing a Parasitic Draw. Found the affected circuit.

[CanuckQx4]

Hey guys, so I have noticed that if my 2001 Qx4 sits for any extended period of time, the battery voltage drops and the car needs a boost to run. Today I researched how to test for parasitic draw and the methods etc and found what I believe to be the affected circuit, but dont quite understand a few things.

The biggest twist to this is my car having aftermarket audio wiring and upgraded alternator power wire and ground cables. The wiring not being stock. I am getting a large amperage draw on the BAT 40amp fuse on the underhood fuse box.

I am testing for an amperage draw on the battery with a test light, with the negative cable disconnected, one probe of the test light on the battery negative post, and the test light clamp on the disconnected battery negative cable.

The test light is illuminated, showing a draw, but if I pull the 40amp BAT fuse the test light will go out.



While looking at the wiring diagram ( which I really dont understand ) I notice they mention fusible links and I located 2 going to the battery positive but they appear to look good.



As you can see my cars power wires were all converted to eyelet style for the audio battery terminals compared to a post. The left side white wires are what I suspect are the fusible links. The fattest middle wire goes to my alternators 12V+ output post (has a big inline fuse) and the 3rd thick copper terminal is the factory battery + wires. The copper eyelet terminal is the only wire that doesnt trip the test light when reconnected to the battery positive post. Only the other 2 have a draw?

I dont see anything wrong with the wiring or how any shorts could be happening but maybe there are things on the 40amp BAT fuse circuit that I should be looking at?

Appreciate some insight on how to further diagnose and rid myself of this draw if I am indeed looking at the right spot.

Cheers

[yngw13]

This only started when you upgraded the audio power lines right?

There is a thing that you can install that will cut off the +/power from the battery.

Power Relay Switch aka RELAY aka Battery Isolator....

When you have a hunch out of the 3 wires...maybe you can install the isolator and maybe in the process rid of the drain...

just my 2 cents...

[Slumpert]

Maybe the factory amplified speakers trigger wire were connect to constant 12v source vs. Switched as theyshould be

[CanuckQx4]

This isnt just from after the stereo, the stereo and wiring has been in it like this for a long while, just the car has sat and if it isnt started daily, the battery voltage drops to low

I dont quite get what you meant slumpert

[yngw13]

then you might have an issue with either the battery/alternator...assuming you havent checked out the charging voltage///or the age of the battery...


I think what Slumpert meant is that the 12v attached to the amps (TURN ON SIGNAL) is a constant live 12v line...and not the ignition triggered 12v line from the fuse box...hence causing a drain ---so the amp might have drain unless it shows that it has an power on indicator light...its worth checking maybe

[CanuckQx4]

Charging voltage is good @ 14.3 volts, battery is a fresh Shuriken and passes load and voltage test

I have no aftermarket amps installed in the car right now either, so nothing drawing power there

Does the light turning off when I pull the BAT 40amp fuse not pinpoint it a bit better to a certain circuit/area on the car I can look

[Slumpert]

From thefactory you have amps if you had the BOSE system..When the stereo was replaced they might have left those amps iin and left them wired Ơn all the time.

[CanuckQx4]

Yes this truck did have the Bose system, cd player is changed to a pioneer and the door speakers are all 6.5" aftermarket.

I am unsure how many amps the car would have or where they would be from the factory, but I imagine I removed them, I slightly recall when i removed the stock front speakers, removing small amps in each front door, but I really dont fully remember, cruddy memory.

I dont understand the wiring diagram enough to figure if the stereo amps run on the BAT 40amp fuse. Wish I knew how to understand that

[Towncivilian]

Try pulling the audio amp relay. Page EL-439 of the FSM shows its location. Might as well remove the rear speaker amp altogether too if it's unplugged.

[CanuckQx4]

I will go pull that rear interior panel off, gosh that fsm is useful eh!

I'll report back

[CanuckQx4]

Got the whole panel off with no broken clips woo!

Anyways what I am seeing is a little different than the FSM says is there, first difference I noticed was the connector for the rear wiper amp was in a different spot, they show it pointing to the left while mine actually is on the bottom.

So then searching for the Audio Amp relay B47, they show ghosted behind the panel, I have nothing there, nothing in the area. The 2 relays they show are stacked behnd eachother, while mine are side by side. The left one you can see has a thick red wire going to it.

Anyways I pulled the bose amp connector, and the connector with the big red wire, and Im still showing a power draw on the 40 AMP BAT fuse circuit. So Im stumped on what to check, not sure I quite found the amp relay.





What do you guys suggest

[Slumpert]

Okay sounds like you can rule out the stereo now. Next I would use a multi meter and check to see how much current is really being drawn. It is possible the power on load could fry the el cheapo freebie one from harbor freight. But unless you have a inline fuse on your meter I would just use a free one.

Do not turn the key on while on meter.. Well unless you like to see them smoke.

Once you have actual. Load reading pull 5 fuses at a time. (photograph first) and recheck actual amperage drain.

Ecu and factory alarm will always pull some, that your should be able to measure. Never tried the clock but it might have a few milliamps of draw in standby.

[CanuckQx4]

I dont trust my meter so I gave up on actually getting any draw data.

But I did do the fuse pulling test, instead of measuring the draw and pulling fuses, I used a test light. As exactly shown in my first picture with the test light lit up.

clamp on the disconnected negative battery cable, probe on the negative post, and if the light is ON there is a draw, if it is off there is not.

*shows how I have the test light hooked up on the negative side*


I have only checked the underhood fuse box with the test light so far but narrowed it down to a parasitic draw coming from the 40AMP BAT circuit, when that fuse is pulled the light goes off.

I seen the test light used to check for draws in quite a few videos so Im hoping its adequate to narrow this down.

[Towncivilian]

I don't recall seeing an audio amp relay when I had the panel pulled either. I wanted to pull mine but couldn't find it. Odd, I guess it's a typo in the FSM.

Have you made any progress narrowing down the draw?

[CanuckQx4]

Yes I think I found it, my older pioneer cd player was drawing 1.5amps continuously, which is much to much from what Ive gathered through research. It has a broken button on it that has always botherred me and a few dead pixels so for now I just pulled the cd player out and disconnected the harness and for I think 4 days now the voltage has only dropped from 12.75 to 12.6 volts. And I didnt let the battery rest a while before checking voltage after taking the charger off, so i probably didnt loose much at all of current. So I think problem solved

Although replacing a pioneer premier cd player isnt going to be cheap