12v Accessory Fuse Blown

Griddlez

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Using an invertor with the 12v plug in the trunk, I believe I may have blown the associated fuse as I can no longer get power from the outlet. I have a few questions about replacing the fuse for this that weren't super clear to me by searching around the forums.

The best I can tell the fuse for this is in main fuse box under the luggage compartment in the front of the car and it is one of the 20a fuses like 61.. or 71. I could not figure out exactly which one it was by searching around but I believe it is one of those. Per this site here (page 277/278): https://www.fordservicecontent.com/...wners-Manual-version-1_om_EN-US_09_2020-1.pdf

Now my real questions come form from gaining access and removing this fuse box to change the 20amp fuses.

Is it possible to get the the fuse box out without having to remove the full center luggage piece? First the owner manual says to remove the luggage compartment covers. I did this but getting access to the fuse box is still kind of tough. Do you really have to remove the center piece? It doesn't seem like the manual says to do that.. just the covers.

Next, do you have to disconnect the main battery proper or by sliding out this fuse box assembly thing, does it disconnect it for you? If you do have to disconnect the main battery where are instructions to do that? It seems gaining access to the red terminal of the battery would be difficult and even the "jumping" the car instructions doesn't have you interacting with the battery terminals directly.

Thanks for any help, if there are any videos showing out to properly gain access to this fuse box and folks know the links to them, that would be greatly appreciated. Thanks!
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Griddlez

Griddlez

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I wanted to reply to this so folks searching around could be aware of this information I gained. I ended up getting the dealer to help me with this (it was covered under warranty). The following is what the dealer/service department did.

First Question: Even though the manual doesn't state it, yes you indeed do need to remove the "bucket" (full center luggage piece) to gain proper access to the fuse box under the hood. This piece is removed after the surrounding "luggage compartment covers" are removed.

Second Question: Yes, they fully disconnected the 12v battery to mess around with the slide-out fuse box. It was easy to do this once the "bucket" mentioned in question 1 was removed. Without it being removed gaining access to the red terminal would have been difficult.

Hope this helps someone in case they also have a blown fuse.
 

Jessnyc

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hey @Griddlez - how long did this process take for with the dealership? I think the same thing might have happened to me, but in the front center console cig port.
 

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Yes, it is very difficult to remove the underhood fuse box without removing the frunk tub. It may be possible if you move the connectors out of the way, I haven’t tried yet. If you are not comfortable with removing underhood parts, it would be best to have your dealer replace the fuse. You also need to be very careful with the large connectors to avoid bending the pins.

To avoid this issue, never use more than a 150W inverter in the 12V ports. Inverters larger than 150W should not come with a 12V plug IMO.
 
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Griddlez

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hey @Griddlez - how long did this process take for with the dealership? I think the same thing might have happened to me, but in the front center console cig port.
When I brought it in they had me in and out within the same day. After drop off.. maybe 3-4 hours? I doubt they worked on it that whole time though.
 


Bayviews88

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When I brought it in they had me in and out within the same day. After drop off.. maybe 3-4 hours? I doubt they worked on it that whole time though.
I just had a similar situation happen with my 12 volt plug and it stopped working. Thank you for this thread - I likely would have been stuck trying to remove the luggage tub! I’m taking my car to the dealer this week.
 

squirreltech

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any idea how much load you used to blow the fuse? at 12 v 20 Amps you should be able to have 240Watts... what were you using when it blew? curious because I'm about to buy a 300W inverter and just be aware not to go over 240W. I need the higher capacity to charge my 230W (19.5volts@ 11.8amps) max laptop.
 

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any idea how much load you used to blow the fuse? at 12 v 20 Amps you should be able to have 240Watts... what were you using when it blew? curious because I'm about to buy a 300W inverter and just be aware not to go over 240W. I need the higher capacity to charge my 230W (19.5volts@ 11.8amps) max laptop.
I'd be careful with that -- those inverters are inefficient and you'll likely burn it out trying to charge a laptop whose power brick's output is 240w. You're likely going to need ~300w of power to do that.

One of the MME shortcomings is lack of 120v outlet. It should have included the 2.4kW inverter from the hybrid / lightning F150s. My truck can charge an EV w/ a 30a 240v charger, or whatever else I'd like to power with the larger 7.2kW inverter.
 

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I'd be careful with that -- those inverters are inefficient and you'll likely burn it out trying to charge a laptop whose power brick's output is 240w. You're likely going to need ~300w of power to do that.

One of the MME shortcomings is lack of 120v outlet. It should have included the 2.4kW inverter from the hybrid / lightning F150s. My truck can charge an EV w/ a 30a 240v charger, or whatever else I'd like to power with the larger 7.2kW inverter.
I figure as long as I'm not gaming or doing anything high intensity it should use far far less then 240W. will likely come in around 140-150 watts max for what I'll be using it for. It only draws max load when the GPU and CPU are both fully engaged (playing a modern AA game on ultra settings at 1080P) not something that I'll be doing while it's in use in the car.
 

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I figure as long as I'm not gaming or doing anything high intensity it should use far far less then 240W. will likely come in around 140-150 watts max for what I'll be using it for. It only draws max load when the GPU and CPU are both fully engaged (playing a modern AA game on ultra settings at 1080P) not something that I'll be doing while it's in use in the car.
Just buy this 140W USB-C charger: https://www.amazon.com/Charger-Adapter-Charging-WOTOBEUS-Samsung/dp/B0BQR1BSSJ/
 

squirreltech

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any idea how much load you used to blow the fuse? at 12 v 20 Amps you should be able to have 240Watts... what were you using when it blew? curious because I'm about to buy a 300W inverter and just be aware not to go over 240W. I need the higher capacity to charge my 230W (19.5volts@ 11.8amps) max laptop.
That must be a beast of a laptop. Back when I carried such animals, Dell’s “large” charger was 130W.
 

dtbaker61

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any idea how much load you used to blow the fuse? at 12 v 20 Amps you should be able to have 240Watts... what were you using when it blew? curious because I'm about to buy a 300W inverter and just be aware not to go over 240W. I need the higher capacity to charge my 230W (19.5volts@ 11.8amps) max laptop.
You should probably connect directly to the 12v connection points rather than thru acc port. I think it is a good idea to have easy access to these points, and the HV disconnect, regardless....

https://www.macheforum.com/site/thr...n-points-hv-disconnect-relay-for-safety.4107/
 

dtbaker61

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I wanted to reply to this so folks searching around could be aware of this information I gained. I ended up getting the dealer to help me with this (it was covered under warranty). The following is what the dealer/service department did.

First Question: Even though the manual doesn't state it, yes you indeed do need to remove the "bucket" (full center luggage piece) to gain proper access to the fuse box under the hood. This piece is removed after the surrounding "luggage compartment covers" are removed.

Second Question: Yes, they fully disconnected the 12v battery to mess around with the slide-out fuse box. It was easy to do this once the "bucket" mentioned in question 1 was removed. Without it being removed gaining access to the red terminal would have been difficult.

Hope this helps someone in case they also have a blown fuse.
It still amazes me that Ford put a fuse block in a location that requires removal of trim and Frunk tub to get to..... and even worse if the Acc power port fuse is there instead of in the passenger footwell fuse block since that is one that probably more than one person is going to blow eventually by plugging in too much load on several power ports.
 

squirreltech

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It still amazes me that Ford put a fuse block in a location that requires removal of trim and Frunk tub to get to..... and even worse if the Acc power port fuse is there instead of in the passenger footwell fuse block since that is one that probably more than one person is going to blow eventually by plugging in too much load on several power ports.
yeah agreed... that ford engineer that designed that should be ashamed of that decision!
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