****REGARDING DEAD HYBRID MAVERICKS ISSUE****

[Klege]

Here is a new one for you. I am dead in the water right now too.
I did the "fix" in February already. As you can see in the first picture. All good since then. Recently I noticed that the screen reset some time while the truck was off. It happened a few times but never a dead truck. Then a few days ago after leaving a restaurant the truck was dead but came alive after a few minutes cusiing at it. Then this morning it was dead again. This time for real. Got the meter out and sure engough I got 3.6 volts under the hood. I figured I check my cable again. Once diconnected I had 12 volts coming from the battery. When connecting back to the terminal it dropped to 3.6 volts again. I figured I follow the path of flow and started to disconnect the cable that goes to the 125 amp fuse. Once disconnected I had 12 volts all across the distribution plate. So I connected the small cable with a short wire to the cable coming from the battery and the voltage dropped to 3.6 volts. I took of the wrap all the way to the bare wire until I had a solid connection and tried again. Same result. I don't know what that cable coming from the 125 amp fuse is for and where it goes but it prevents the truck from even taking a jump. We are towing the truck behind our RV and it now sits at a Ford Dealership in Las Cruces, NM. They have never even heard of the first issue, let alone this one and only 3 technicians that are hybrid certified. God only knows when they will be able to look at it. I am suspecting a loose connection somewhere down that cable or a related failed ground connection. But where to even look for it.

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[OleFordGuy]

I seem to recall a post or video or something a while back where they replaced the entire fuse box

 

[rivermaverick]

Here is a new one for you. I am dead in the water right now too.
I did the "fix" in February already. As you can see in the first picture. All good since then. Recently I noticed that the screen reset some time while the truck was off. It happened a few times but never a dead truck. Then a few days ago after leaving a restaurant the truck was dead but came alive after a few minutes cusiing at it. Then this morning it was dead again. This time for real. Got the meter out and sure engough I got 3.6 volts under the hood. I figured I check my cable again. Once diconnected I had 12 volts coming from the battery. When connecting back to the terminal it dropped to 3.6 volts again. I figured I follow the path of flow and started to disconnect the cable that goes to the 125 amp fuse. Once disconnected I had 12 volts all across the distribution plate. So I connected the small cable with a short wire to the cable coming from the battery and the voltage dropped to 3.6 volts. I took of the wrap all the way to the bare wire until I had a solid connection and tried again. Same result. I don't know what that cable coming from the 125 amp fuse is for and where it goes but it prevents the truck from even taking a jump. We are towing the truck behind our RV and it now sits at a Ford Dealership in Las Cruces, NM. They have never even heard of the first issue, let alone this one and only 3 technicians that are hybrid certified. God only knows when they will be able to look at it. I am suspecting a loose connection somewhere down that cable or a related failed ground connection. But where to even look for it.

Nice diagnostic work - I wish we could get hybrid wiring diagrams without buying the complete Ford manuals.

 

[MakinDoForNow]

Here is a new one for you. I am dead in the water right now too.
I did the "fix" in February already. As you can see in the first picture. All good since then. Recently I noticed that the screen reset some time while the truck was off. It happened a few times but never a dead truck. Then a few days ago after leaving a restaurant the truck was dead but came alive after a few minutes cusiing at it. Then this morning it was dead again. This time for real. Got the meter out and sure engough I got 3.6 volts under the hood. I figured I check my cable again. Once diconnected I had 12 volts coming from the battery. When connecting back to the terminal it dropped to 3.6 volts again. I figured I follow the path of flow and started to disconnect the cable that goes to the 125 amp fuse. Once disconnected I had 12 volts all across the distribution plate. So I connected the small cable with a short wire to the cable coming from the battery and the voltage dropped to 3.6 volts. I took of the wrap all the way to the bare wire until I had a solid connection and tried again. Same result. I don't know what that cable coming from the 125 amp fuse is for and where it goes but it prevents the truck from even taking a jump. We are towing the truck behind our RV and it now sits at a Ford Dealership in Las Cruces, NM. They have never even heard of the first issue, let alone this one and only 3 technicians that are hybrid certified. God only knows when they will be able to look at it. I am suspecting a loose connection somewhere down that cable or a related failed ground connection. But where to even look for it.

Consider that wire could be involved in closing of hvb relays and also there could be a bad ground within or of the box. The wire with 3.6v which plugs into the 125 amp probably needs to have at least 6/8/? Volts to trigger relay. Does the wire have the 12v when it's unplugged and drops to 3.6 when plugged in? You may be on to something here.

 

[Darnon]

I don't know what that cable coming from the 125 amp fuse is for and where it goes but it prevents the truck from even taking a jump.

That's the power connection from the Underhood Junction Box to the Body Control Module.

 

[Klege]

That's the power connection from the Underhood Junction Box to the Body Control Module.

Thank you for that info.

 

[Klege]

Consider that wire could be involved in closing of hvb relays and also there could be a bad ground within or of the box. The wire with 3.6v which plugs into the 125 amp probably needs to have at least 6/8/? Volts to trigger relay. Does the wire have the 12v when it's unplugged and drops to 3.6 when plugged in? You may be on to something here.

Darnon informed me that that's the power connection from the Underhood Junction Box to the Body Control Module.
Once you apply 12 volts to the cable, it drops to 3.6 volts. So, either some bad connection somewhere within the cable itself or ground or maybe a bad BCM.
It's definitely an interesting one. And it's sad that we must do all the digging for answers. Dealers really should be updated by Ford on well-known issues. At least this dealer was really interested in what I had diagnosed so far. You don't get that too often.

 

[Darnon]

Once you apply 12 volts to the cable, it drops to 3.6 volts. So, either some bad connection somewhere within the cable itself or ground or maybe a bad BCM.

Or something connected to the BCM is overdrawing/dumping current to ground as it's functionally the passenger footwell power distribution fusebox.

 

[Klege]

Or something connected to the BCM is overdrawing/dumping current to ground as it's functionally the passenger footwell power distribution fusebox.

LOL, you can't make this easy can you?
Well, we will leave the truck behind and enjoy Phoenix and the Grand Canyon for the next two weeks. Hopefully, they figure it out here and don't take too long. Although I admit that I am itching to figure this out. As much as this is a pain in the rear end I kind of love to be challenged like this.

 

[Dad]

Darnon informed me that that's the power connection from the Underhood Junction Box to the Body Control Module.
Once you apply 12 volts to the cable, it drops to 3.6 volts. So, either some bad connection somewhere within the cable itself or ground or maybe a bad BCM.
It's definitely an interesting one. And it's sad that we must do all the digging for answers. Dealers really should be updated by Ford on well-known issues. At least this dealer was really interested in what I had diagnosed so far. You don't get that too often.

Great reporting and sharing of a vital issue with the Maverick. I agree . . . I feel like we are a separate troubleshooting and repair department of FMC, but without the payroll. I know many manufacturers will roll out products and use consumers as "beta" testers. I wonder if Ford did so with the Maverick in the interests of faster production. No matter, let's see where this goes. Again, thanks.

 

[MakinDoForNow]

Darnon informed me that that's the power connection from the Underhood Junction Box to the Body Control Module.
Once you apply 12 volts to the cable, it drops to 3.6 volts. So, either some bad connection somewhere within the cable itself or ground or maybe a bad BCM.
It's definitely an interesting one. And it's sad that we must do all the digging for answers. Dealers really should be updated by Ford on well-known issues. At least this dealer was really interested in what I had diagnosed so far. You don't get that too often.

Have you considered alerting Ford rep that monitors this site? Might help get better contact to see icing dealer????

 

[Nw_adventure]

And don't forget the Smart battery junction unit under the hood. Mine was causing issues and was replaced -

 

[TedTX]

3.6 …. That is suspiciously the voltage of a single lithium ion cell… bet the top most cell is poor and the system is draining it to level the pack. If it still looks high the thing gets drained to GROUND. Grounding the whole DC-DC module, Capacitor installed with wrong poles swapped feeding back a charge.
Just a wild guess. I’m no expert.

 

[Klege]

Have you considered alerting Ford rep that monitors this site? Might help get better contact to see icing dealer????

This dealer is actually pretty cool and thankful for all the info I could give them.

 

[Klege]

3.6 …. That is suspiciously the voltage of a single lithium ion cell… bet the top most cell is poor and the system is draining it to level the pack. If it still looks high the thing gets drained to GROUND. Grounding the whole DC-DC module, Capacitor installed with wrong poles swapped feeding back a charge.
Just a wild guess. I’m no expert.

No, I am talking 12 volt system only.

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