I think I messed up my car guys- Urgent help needed!!

[Ghostrealm]

I recently tried to hook up a new battery one of those lithium Ion antigravity batteries for my 2017 Mustang. I screwed up and reversed the terminals. The car drove for 1 min but then conked out. I then put a brand new lead acid in to the car and it drives howerver keep seeing " Service charging system now.

I tested the battery terminal with a multimeter and it is 12.2 volts when car is off. when i turn the car engine on it goes to 11.5 which seems strange as it goes even lower.

I reset the battery BMS by pulling the headlight lever and pushing the brake 3 times and it reset. Still the " Service charging system now. error comes on.

I hooked up an obd code reader and it says 1 error. The error reads

p068a
Stored
ECM/PCM Power Relay De-Energized
Performance- Too Early

Could I of short circugited something when I reversed the battery as it did spark and smoke from the positive terminal when I did that.

I reset the code with the obd scan rtool and it says I have no errors but the battery light is still on and " Service charging system now still shows.

Does anyone know what fuse might of blown or if I just need to replace the PCM fuse?

Please guys its so urgent and need your advice.

Much appreciated, I look forward to any and all of your help.

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[Jaymar]

If the voltage drops when running you probably aren't getting charge from the alternator. Check the fusible link from the alternator and hope that it that and not the regulator. May have discharged backwards against the reversed battery and blown the fuse.

 

[Ghostrealm]

Where do I check for this fusable link? I definately blew some sort of fuse. Where is the alternater fusebale link?

 

[Jaymar]

I don't know for sure, I'd check all the fuses in the underhood box. Follow the large line back from the alternator to the fuse block/battery and look for any large fuses. I don't exactly what this car has but that is how most all modern cars are wired.

 

[Jaymar]

Certainly try this one:

 

[Ghostrealm]

Thank you so much. Would anyone know where this fuse is located? I am so terrible with cars etc.

 

[Ghostrealm]

Thank you!!! This is the fuse for the alternator 36?

 

[Jaymar]

No, it's only 10A but it's labeled alt sense so I'd guess that it may have something to do with the alternator. Realistically after reversing the polarity of a battery you should check all of the fuses so there are no surprises. That's why the fuses are there, to protect against large overcurrent events such as that.

 

[Ghostrealm]

Could a relay also blow? Is there a way to visually inspect a relay? Thanks Again guys honestly its very much appreciated all your help.

 

[Jaymar]

Generally they don't blow. There is usually a fuse that will let loose before a relays contacts are damaged.

 

[Ghostrealm]

So just check every fuse under a light to make sure it looks like a horseshoe and no and "h" where you could see it broke? just all the fuses in the fusebox under the hood?

 

[Torinate]

May help.

https://www.mustang6g.com/forums/threads/fusible-link-for-alternator.123800/

 

[Jaymar]

So just check every fuse under a light to make sure it looks like a horseshoe and no and "h" where you could see it broke? just all the fuses in the fusebox under the hood?

Yes. Or better if you have a voltmeter test both pins sticking out of the top looking for voltage that exists on one side and not the other. Or pull it and test continuity.

 

[Ghostrealm]

So basically its looks like the part for the megafuse is part # FU5Z-14526-A ?

Can you kidnyl confirm? this should most liekly fix the error? They said they also had the service charge system now message and it fixed when they changed out this megafuse.

 

[Ghostrealm]

Torinate are you a mechanic? Would it be ok to come to you for service? Can you repair cars? Im in Ontario too.

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