Need guidance on replacing the alternator.

[MattC0509]

I have a 2020 ST with 54k miles and recently had to replace the battery for a second time. Shortly there after I received intermittent warnings about checking the 12v charging system. This persisted for about a week with no issues start up or other wise. It became a consistent warning that came up every time the car was driven so I had the alternator tested today and it failed. I am in the process of replacing the alternator but cannot seem to get the old one free. Does anyone have any insight on the best way to remove the alternator and/or access the bottom side and wiring connections on the rear?

 

[ButchsExplorerST]

Here are some pages from service manual, hope they help.

 

[MattC0509]

Thanks for the info and I did get it figured out. Unfortunately charging issues never went away. Got in down the street to a local Pep boys and the alternator was testing as bad only putting out 12.4v under load. Seemed odd that a brand new alternator could be bad right out of the box but nothing is impossibly so I was able to get another installed today. Immediate charging issues so I run forscan and am getting 12.49 volts at the battery. No way I had two alternators back to back be bad. Anyone have any thoughts on anything to check or look for? Nothing else has been disconnected during the alternator replacements. That said It was at a Ford dealer for 2 months having the transmission rebuilt and replacing the rear. Battery issues and subsequent charging issues occurred 4 days after picking it up from the dealer.

 

[ButchsExplorerST]

I had multiple charging and starting issues with a AutoZone battery. Had to be tow into Dealership, they replaced the battery with Motorcraft battery now it overcharge sometimes up to 16.1 volts

 

[MattC0509]

I had multiple charging and starting issues with a AutoZone battery. Had to be tow into Dealership, they replaced the battery with Motorcraft battery now it overcharge sometimes up to 16.1 volts

The battery is an Interstate AGM from Costco and the guy at Pep Boys felt like the charge on it was good and issues were coming from the alternator. There's clearly a gremlin somewhere in the system but unsure what else to look for.

 

[GearHead_1]

Probably a silly question, but did you do a BMS reset?

 

[MattC0509]

Probably a silly question, but did you do a BMS reset?

Yeah I've done multiples now in Forscan between the battery change and alternator changes. Got the second new alternator in around lunch and went and drove 5 miles...did the BMS reset and the car died in the middle of it.