Electrical issues with my 2006 mustang GT

vernevdv

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Hello. Suddenly at work my remote key stopped working. I thought the battery would have ran out. Later that day I wanted tot drive my car but when I started it. It gave me multiple warnings. Fuel level sender fault, oil pressure low, fuel and oil gauge on zero, traction control permanently off, handbrake on. Lights, blinkers, brake light, ac, radio also stopped working. I figured it might be water damage to the sjb. I opened it up and checked for corrosion or watermarks but I found neither. I checked female connectors and those also looked fine. Checked and cleaned all fuses in both fuseboxes. Removed aftermarket radio. After resetting by removing battery terminals nothing changed. Battery and alternator seem both fine. 12.7 battery, 14 volts with engine on. I started looking for bad grounds. Anyone who can help me out here? 2006 4.6 mustang gt.
 

Juice

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These bot posts are getting out of hand. WTF
 

07 Boss

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The alternator seems fine??? You should go have it tested and make sure they test the diode. The symptoms you describe are often caused by the alternator going bad. The voltage might be correct but a bad diode can cause these issues. If you do replace it get one for a 2010. It's a different spec than the ones for 05-09.
 

vernevdv

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The alternator seems fine??? You should go have it tested and make sure they test the diode. The symptoms you describe are often caused by the alternator going bad. The voltage might be correct but a bad diode can cause these issues. If you do replace it get one for a 2010. It's a different spec than the ones for 05-09.
Thanks for your reply boss. I will check AC ripple first and then check the diode.
 

vernevdv

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Hello. Suddenly at work my remote key stopped working. I thought the battery would have ran out. Later that day I wanted tot drive my car but when I started it. It gave me multiple warnings. Fuel level sender fault, oil pressure low, fuel and oil gauge on zero, traction control permanently off, handbrake on. Lights, blinkers, brake light, ac, radio also stopped working. I figured it might be water damage to the sjb. I opened it up and checked for corrosion or watermarks but I found neither. I checked female connectors and those also looked fine. Checked and cleaned all fuses in both fuseboxes. Removed aftermarket radio. After resetting by removing battery terminals nothing changed. Battery and alternator seem both fine. 12.7 battery, 14 volts with engine on. I started looking for bad grounds. Anyone who can help me out here? 2006 4.6 mustang gt.
Update: a new sbj fixed everything. The old one has no signs of corrosion or waterdamage but was still the problem. Hope this helps someone in the future. I ordered a tested used one from ebay.
 

Reddawg

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The alternator seems fine??? You should go have it tested and make sure they test the diode. The symptoms you describe are often caused by the alternator going bad. The voltage might be correct but a bad diode can cause these issues. If you do replace it get one for a 2010. It's a different spec than the ones for 05-09.
What’s different/better about an alternator from a 2010?
 

Dino Dino Bambino

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What’s different/better about an alternator from a 2010?
The 09-10 GT was fitted with the better quality, more reliable Japanese-made Denso alternator.
That said, you might still be able to find a remanufactured Motorcraft 05-08 GT alternator from a Ford stealership. They're better quality and less failure prone than the originals that were fitted from the factory.
 

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