2005 Mustang electrical issue

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dhay13

Senior Member
Joined
Apr 12, 2015
Posts
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Ram Year
2018
Engine
2500 6.4L Hemi 4.10's 'Off-Road'
Have a 2005 Roush Mustang. Basically powertrain wise just a GT. Back in August my battery died so got a new one from Auto Zone. Drove the car awhile then went to enter it into our towns Halloween parade. While in line went to pop the truck with my key fob but no luck so used the key to open it. Got in the car and started it up but couldn't get it out of park. Noticed all the lights on the dash were lit up and my fuel gauge on E. Had no headlights, tail lights, turn signals or brake lights. Used the shifter interlock bypass and got it home. Power top does not work, no radio, no power windows. In fact, the only things that work are 1) the car starts and runs fine. 2) my power mirrors still work 3) horn still works. So just to eliminate it I take the battery out and take it back to Auto Zone. Only tests at 65%. Odd. So they give me a new one. The car has not been driven since then but has been started here and there troubleshooting but hasn't been started in about 2 weeks. So last night I go down and throw my volt meter on the battery and its only at 2.3 V. Don't see anything in the car that had been left on. Before this I was messing with the BCM as I had read these can cause the same symptoms. I have had the BCM out and can't physically see anything wrong with the circuit board. So last night I checked the fusible link between the battery and alternator and it feels ok. I can't get to the backside of the alternator to get to the other end of the wire unless I remove the CAI and TB but I ordered an adapter to use Forscan on (similar to AlfaOBD. That should be here by the end of the week so I don't want to tear anything else apart until I can run that on it.
Any other thoughts or ideas? Car is an automatic with 38,000 miles and no modifications. Even the original stock stereo. No add on electronics of any kind anywhere.
Thanks!
 
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dhay13

dhay13

Senior Member
Joined
Apr 12, 2015
Posts
3,326
Reaction score
2,982
Ram Year
2018
Engine
2500 6.4L Hemi 4.10's 'Off-Road'
So leaning towards some type of CANBus problem. Possibly alternator causing a break in the network traffic. Waiting on the ELM adapter to get here so I can run the diagnostic scanner on it
 
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