2008 bullitt electrical problems?

[nieo]

Hi everyone, I have a 2008 mustang bullitt that I have been trying to troubleshoot.

fuses 42 and 47 will blow as soon as the ignition is turned. when I disconnect the PCM relay in the fuse box they don't blow and when I disconnect the middle pcm connector they won't blow. I disconnected the c110 connector and pinned it out and found that fuse 47 will blow when the black and white stripe wire (some sort of ground?) is connected, and it and the rest of the connector is still disconnected.

Any ideas for further troubleshooting?
and any chance someone has a pcm wiring diagram?

 

[Forty61]

I would have to see a schematic but it sounds like you're on the right track.. if pulling the connector to the PCM alleviates the fuses blowing then at least you know the problem is upstream of that connection somewhere. I have a shop manual somewhere at home but I don't think the diagrams go deep enough to cover this.. maybe @86GT351 can help with the schematic.

 

[DieHarder]

Well, appears you have a short/active component failure or possibly a diode that's failed. I'd check the PCM Power diode to make sure it's good. Unfortunately, the online manual doesn't show what each fuse services so I'll fill in the blanks. When I have more time I'll delve back into this to see what else I can find in the manuals.


Fuses: https://iihs.net/fsm/?d=40&f=Fuse and Relay Information.pdf

F42: Services PCM; PCM Key Off relay; COPs; Ign Transformer Capacitors 1,2

Ford Workshop Service & Repair Manuals - fordrepair.info - 2005 Mustang 2005 Mustang Power distribution-sjb

Ford Workshop Service and Repair Manuals, 2005 Mustang Wiring Diagrams Power Distribution-SJB

iihs.net

F47: Services A/C clutch relay; EVAP Canister control solenoid; EGR Module; Oxy sensors; VVT solenoids; IMRC; AT; EVAP can purge.
https://iihs.net/fsm/?d=40&f=Manual Climate Control System.pdf&p=2

C110: on the pinout diagram Pin 13 is a ground. Pin 12 is a Black/White wire that services circuit 570. Cannot find 570 on any of the diagrams at the moment. If I do I'll forward it.
Here's a pic of C110:

 

[DieHarder]

Found it:

Reference above: C110 Pin 12/ (Circuit 570) is related to the MAF and engine controls..

See lower right section of the diagram: https://iihs.net/fsm/?d=40&f=Electronic Engine Controls - 4.6L.pdf&p=2

I have seen cases where the MAF wiring has become shorted. In any case there's a lot of items that are interdependent that you'll need to troubleshoot to eliminate a shorting condition.

Also found C110 Pin 13 (see pic diagram right side). Note: This section is in my paper manual but missing from the online version. You'll want to reference the picture to compare.

Picture:





Online version: https://iihs.net/fsm/?d=40&f=Electronic Engine Controls - 4.6L.pdf&p=3

Hope this helps.

 

[nieo]

update, down to just eh fuse 47 blowing! has to be something with the c110 connector as it doesn't blow when disconnected, what possible modules can the c110 connector run too that I could disconnect to test?

 

[DieHarder]

You might try a google search. If you have it down to C110 you need to chase each wire to determine if there are other wires shorting somewhere.

Here's a few articles/references to one I just did: https://www.google.com/search?q=200...A&sclient=gws-wiz&sei=hlJqaZnAI-KBwN4PsZ-90Ac

And the manual: F47: https://iihs.net/fsm/?d=40&f=Manual Climate Control System.pdf&p=2

If no luck may be worth paying for a diagnostic to narrow down the list of culprits.

 

[ryunker]

Here is info from identifix, IMRC wiring, MAF circuit, 03 sensor circuits.

F. Sonny Stankiewicz October 20, 2017		2007 Ford Mustang, Shelby GT 4.6L, V8, Asp N, VIN H, 24V, SOHC, USA * Engine Wiring Harness - found imrc sub harness chewed threw and shorted to ground	Repaired Engine Wiring Harness
2	Auto Specialist January 9, 2019		2008 Ford Mustang, 4.0L, V6, Asp N, VIN N, 12V, SOHC, USA * Engine Wiring Harness	Repaired Engine Wiring Harness
3	MAJORDAVIS April 8, 2016		2008 Ford Mustang, 4.0L, V6, Asp N, VIN N, 12V, SOHC, USA * Engine Wiring Harness	Repaired Engine Wiring Harness
4	Dustin Leger June 17, 2015		2006 Ford Mustang, 4.0L, V6, VIN N, 12V, USA * Engine Wiring Harness	Repaired Engine Wiring Harness
5	Jeff Kobliska November 20, 2013		2008 Ford Mustang, Shelby GT500 5.4L, V8, Asp S/C, VIN S, 32V, DOHC, USA * Engine Wiring Harness	Repaired Engine Wiring Harness
1	Jose Diaz March 8, 2016		2010 Ford Mustang, 4.0L, V6, Asp N, VIN N, 12V, SOHC, USA * Oxygen (O2) Sensor(s) - O2 sensor wire shorted	Replaced Oxygen (O2) Sensor(s)
2	THARPC07 September 25, 2014		2008 Ford Mustang, Shelby GT500 5.4L, V8, Asp S/C, VIN S, 32V, DOHC, USA * Oxygen (O2) Sensor(s) - replaced o2 sensor	Replaced Oxygen (O2) Sensor(s)
3	Ivan Talavera April 7, 2020		2007 Ford Mustang, 4.0L, V6, Asp N, VIN N, 12V, SOHC, USA * Oxygen (O2) Sensor(s)	Replaced Oxygen (O2) Sensor(s)
1	Dean Pappas July 16, 2014		2006 Ford Mustang, GT 4.6L, V8, VIN H, 24V, USA * Mass Air Flow (MAF) Sensor Connector Mass Air Flow (MAF) Sensor Wiring - maf wiring &conector	Replaced Mass Air Flow (MAF) Sensor Connector and Repaired Mass Air Flow (MAF) Sensor Wiring
1	Savannah Tire Richmond Hill June 22, 2015		2007 Ford Mustang, 4.0L, V6, Asp N, VIN N, 12V, SOHC, USA * Mass Air Flow (MAF) Sensor Wiring - Aftermarket air intake moved mass air sensor on top of EGR tube. EGR tube burnt through harness connector causing a short to fuse 47.	Repaired Mass Air Flow (MAF) Sensor Wiring

 

[nieo]

Ok update,

The good: I finally got the fuses to stop blowing and the car does start and run!
( it was the evap sensor in the rear of the car and the c110 connector was just completing the ground to the circuit)

The bad : the car is throwing tons of error codes and the alternator is not recharging th battery, already tried 2 alternators so pretty sure it’s the wiring, the 3 pin connector to the alternator has an orange and blue wire OB, a yellow blue YB and a yellow Y

With the key off OB had 12 volts and the others got none

I did check continuity and ohms across the cable leading to the back of the alternator to check the inline fuse and it looks good, additionally fuse 43 (alternator fuse) is also not blown.

I haven’t gotten too far into this yet, any ideas?


It seem like the problems never stop ‍end

 

[Mustang777]

Glad you found the EVAP issue, but for the alternator not charging, check if you're getting voltage on the yellow wire with the engine running - that's the field circuit from the PCM and if it's not getting signal the alternator won't charge.

 

[DieHarder]

List the error codes you're getting. Then look them up online and in the manual: https://iihs.net/fsm/?d=10

Alternator Charging system: https://iihs.net/fsm/?d=358

Hopefully these help narrow down problem areas.

 

[nieo]

Ok, I just had a bad alternator as the replacement which sucks but it's not too much work, car runs great now except none of my lights work. my headlights and rear parking lights work but nothing else will. when I hit turn signals they flash on the cluster but don't work. and my brake lights don't work either.

I have this crazy long list of SJB codes im guessing I have a bad ground somewhere?

 

[nieo]

found problem, had cracked connector at sjb