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Discussion Starter · #1 ·
Hello,
I could really use some advice.
I have a battery drain where the batery lasts 5-6 days undriven, and using my multi, i determined it was tied to #6 40A fuse under the hood.
#6 indicates Instrument Cluster / Powertrain Control Module.
So i removed the cluster, and unplugged the PCM.
Parasite is still there, how do i proceed after trying these two basic tests?
2003 mach1
 

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I would have removed the fuse and then verify that the draw was gone...
 

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Then you need to get a wiring diagram and trace where fuse #6 power goes to. Just because the label says I/C, PCM does not mean that other components could not draw a current. Is there a relay involved? Does the power feed branch off to the BCM? Lots of things to check than just the PCM and I/C
 

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Discussion Starter · #5 ·
Then you need to get a wiring diagram and trace where fuse #6 power goes to. Just because the label says I/C, PCM does not mean that other components could not draw a current. Is there a relay involved? Does the power feed branch off to the BCM? Lots of things to check than just the PCM and I/C
Thank you for the reply, I will move my search to the wiring diagrams but this section is fairly new to me. I can see many circuits in the manual, is there a way to determine which circuit to focus on? What do i look for in the diagram to narrow it down a bit more?
Air Conditioning Circuit
Ant-Lock Brakes Circuit
Passive Anti-Theft Circuit
Body Control Module Circuit
Computer Data Lines Circuit
Cooling Fan circuit
Cruise Control Circuit
Defrogger Circuit
Engine Performance Circuit
Backup Lamps Circuit
Exterior Lamp Circuit
Ground Distribution Circuit
Headlight Circuit
Horn Circuit
Instrument Cluster Circuit
Courtesy Lamp Circuit
Instrument Illumination Circuit
Power Distribution Circuit
Power Door locks circuit
Power Mirrors circuit
Lumbar Circuit
Power seat circuit
powertop/sunroof circuit
Power Window circuit
Preium Sound Radio Circuit
Shift Interlock Circuit
Charging Curcuit
Starting curcuit
Supplemental restrains circuit
A/T Circuit
Trunk, Tailgate, Fuel door circuit
Waraning system circuit
wiper washer circuit
 

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Discussion Starter · #6 ·
Thank you for the reply, I will move my search to the wiring diagrams but this section is fairly new to me. I can see many circuits in the manual, is there a way to determine which circuit to focus on? What do i look for in the diagram to narrow it down a bit more?
Air Conditioning Circuit
Ant-Lock Brakes Circuit
Passive Anti-Theft Circuit
Body Control Module Circuit
Computer Data Lines Circuit
Cooling Fan circuit
Cruise Control Circuit
Defrogger Circuit
Engine Performance Circuit
Backup Lamps Circuit
Exterior Lamp Circuit
Ground Distribution Circuit
Headlight Circuit
Horn Circuit
Instrument Cluster Circuit
Courtesy Lamp Circuit
Instrument Illumination Circuit
Power Distribution Circuit
Power Door locks circuit
Power Mirrors circuit
Lumbar Circuit
Power seat circuit
powertop/sunroof circuit
Power Window circuit
Premium Sound Radio Circuit
Shift Interlock Circuit
Charging Curcuit
Starting curcuit
Supplemental restrains circuit
A/T Circuit
Trunk, Tailgate, Fuel door circuit
Warning system circuit
wiper washer circuit
Would 'Computer Data Lines Circuit' be the correct one?
wiring1.jpg
 

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now what?
 

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Discussion Starter · #9 ·
Taking a fresh attempt now using the diagram.
Fuse 39 5a is yellow, bottom right in diagram 3.
On that same block are the following:
---
Fuse 33 - Deactviator Switch & Brake Pedal Positioning Switch
Fuse 27 - Radio
Fuse 21 - Instrument Cluster, Powertrain Control Module
Fuse 15 - Left Front Lumbar Adjust Switch
Fuse 9 - Front Subwoofer Amplifier and Rear Subwoofer Amplifier

It says 'from splice s260 on diagram 1 of 3' under the hood:
Fuse 13 - Electronic Flasher Module
Fuse 6 - 40A

It says 'To fuse 27 Diagram 3 of 3'
Fuse 27 - Radio
---
1a.png
1b.png
1c.png

I am going to remove Fuses 13, 33, 27, 21, 15, 9 and re-test after 45 mins.
I don't have aligator clips, i hope i'm not waking it up by when using the multi.
 

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I would start here:

Preium Sound Radio Circuit
Fuse 9 - Front Subwoofer Amplifier and Rear Subwoofer Amplifier

It is a well known issue that the Mach 460 Amps can cause a parasitic drain. It appears that when they age the relay or circuit that turns the power off fails. Unplug the cables from the amps (behind the rear seat in a vert, mounted under the rear speaker panel on a coupe). See if the drain stops. If it does you know one or both amps are bad.
 

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Discussion Starter · #11 ·
I would start here:

Preium Sound Radio Circuit
Fuse 9 - Front Subwoofer Amplifier and Rear Subwoofer Amplifier

It is a well known issue that the Mach 460 Amps can cause a parasitic drain. It appears that when they age the relay or circuit that turns the power off fails. Unplug the cables from the amps (behind the rear seat in a vert, mounted under the rear speaker panel on a coupe). See if the drain stops. If it does you know one or both amps are bad.
Thank you, Would removing fuse 9 accomplish the same thing? (i removed it a while ago)
 

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Discussion Starter · #14 · (Edited)
According to Ford, the GEM can drawn power for up to 40 mins after shut off.
You can read about it here:

GEM MODULE DRAWING POWER WHEN VEHICLE IS OFF!!! - MustangForums.com
Good catch, Thanks
I'll remove both fuses 13 and 15 permanently, I've been waiting 1-2hrs for it to cool down before testing.
Also learned from your shared article:
NOTE: It is very important that continuity is not broken between the battery and the negative battery cable when connecting the meter. If this happens, the entire procedure must be repeated.

I think I'll use electric tape to hold the prongs in place on the negative.
 
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