disconnected negative battery - now won't start

[jorosz0309]

Has anyone disconnected your negative battery terminal and reattached it.....did you have any problems? I had my negative disconnected for a few minutes so I could attach my amplifier power cable to the positive terminal. Then when I re-connected the negative, it gives me about a dozen alerts and won't start. Full power / accessory mode, but won't even try to turn over. Says service engine soon. Any ideas?

Sponsored

 

[jorosz0309]

Any reason why you disconnected the negative terminal?

did you have the positive terminal disconnected already when you disconnected/reconnected the negative terminal?

Just standard practice to disconnect the negative battery terminal when adding electronics to avoid shorts. Positive stayed connected the whole time. I just watched a you tube video about resetting the Battery Monitor Sensor (accessory on, flash high beams 5x, step on brake 3x, place fob in programming slot, start) and it started right up. I hate that cars are so complicated now that you can’t simply disconnect the battery without fear of being stranded. Oh well, figured it out with the help of youtube.

 

[Hoss]

Wow

 

[Gary Brantley]

I just watched a you tube video about resetting the Battery Monitor Sensor (accessory on, flash high beams 5x, step on brake 3x, place fob in programming slot, start) and it started right up.

Man, that is crazy! Let ask a question or two; what does "accessory on" mean and does "place fob in programing slot" mean inserting the key? I'm asking because I can sure see this happening to me too. Thanks for any help!

 

[jorosz0309]

Man, that is crazy! Let ask a question or two; what does "accessory on" mean and does "place fob in programing slot" mean inserting the key? I'm asking because I can sure see this happening to me too. Thanks for any help!

accessory on means, push the button to turn the electrical system on (without pushing on the brake... don't turn the truck engine on)
the key programming slot is a small depressed area the size of your key fob, located at the bottom of the center storage console between the driver and passenger seats.

Seems as though others have disconnected their batteries without incident, but it also seems that if you google the topic both the BMS and the security system both sometimes cause faults after a battery has been disconnected. In most cases it seems that this reset works. Apparently there are a few other "routines" or combinations of actions that will do the same thing, but this was the most popular one I could find for Fords.

 

[Gary Brantley]

Thanks for the reply! I just realized this thread is in Raptor section. D'oh!

I have a 2024 STX and I don't think it has those features, or at least I don't know about them!

Sponsored