Check Your Fuse #71

[micl9]

Not to mention Ford using 7 different types of fuses in one vehicle. Gonna cost me a fortune to buy spares. ?

Yeah what's up with that!?
And unless I overlooked it, this is the 1st vehicle in years that doesn't have a fuse picker included at the box.

Sponsored

 

[Motorpsychology]

Ok, so I gave in and went out to the garage and checked mine. What a PITA to get to the fuse. Dumbest design ever for a fuse box location and access. Hey Ford give me an inch more slack on the cable so I can get the box out, please. Checking the latest version of the manual online, it calls for a 25A fuse. I have a 25A fuse installed in position #71. Curious what documentation available calls for a 30A fuse?

That’s a great question. Now I’m even more confused.

Attaching the description portion of my work order…

This is getting interestinger and interestinger. The owners Manual does call for a 25A in #71, but according to the tech, the WorkShop Manual calls for a 30A. I wonder if there is a real discrepancy or if the tech was "shooting from the hip" and didn't realize the spec was changed in 2020?

 

[Motorpsychology]

That’s a great question. Now I’m even more confused.

Attaching the description portion of my work order…

@Gil-galad:
Hang on to that work order.
If the spec is truly 25A, then any problems stemming from a too-high capacity fuse could exempt Ford from responsibility, or void the warranty, unless you have the proof that the dealer installed it.
I would calmly ask the Service Supervisor to show you the WSM spec and show him/her the Owners Manual spec (p255).
If there is a misprint, then Ford needs to correct it, or maybe it has been: somebody mentioned the possibility of a TSB on this.

 

[Gil-galad]

@Gil-galad:
Hang on to that work order.
If the spec is truly 25A, then any problems stemming from a too-high capacity fuse could exempt Ford from responsibility, or void the warranty, unless you have the proof that the dealer installed it.
I would calmly ask the Service Supervisor to show you the WSM spec and show him/her the Owners Manual spec (p255).
If there is a misprint, then Ford needs to correct it, or maybe it has been: somebody mentioned the possibility of a TSB on this.

Good advice. In the end, I’m not going to lose any sleep over it. My trailer lighting is all LED and doesn’t draw a lot of current under normal operation. It all seems good for now. If moisture intrusion or some other unknown factor eventually recreates itself and causes a short, the 30A fuse isn’t going to last much longer than a 25A would have.

 

[Motorpsychology]

Yeah what's up with that!?
And unless I overlooked it, this is the 1st vehicle in years that doesn't have a fuse picker included at the box.

Those cobby plastic ones are clumsy when trying to pull those micro fuses. I got a couple of these, one I keep in the glove box, the other in my tool box.

 

[Dgc333]

Check the manual and look in the engine compartment. Not the case for this fuse.

Wow! I did not realize that there were fuses on the bottom side of the engine compartment fuse box.

 

[Peragrin]

This reminds me of when i purchased my 2016 jeep liberty. I purchased one with dual mysky panels(the roof panels were removable)

I had the sales guy show me the unlock and removing feature of both panels. In a snow storm in Januaray in New England.

The panel got stuck in the open position. 2 service techs and the saless man disassembled the roof panel and was able to manually lock it back into place. Took them 2 hours.(a lot of it was what the f is it catching on)

Got new panels a week later.

Doing a walk atound and checkibg how things are supposed to work is always a good thing

 

[Bsqrd]

Wow! I did not realize that there were fuses on the bottom side of the engine compartment fuse box.

Yeah and the lid is pretty flimsy. Be careful trying to remove it. Big PITA!

 

[Texasota]

Good advice. In the end, I’m not going to lose any sleep over it. My trailer lighting is all LED and doesn’t draw a lot of current under normal operation. It all seems good for now. If moisture intrusion or some other unknown factor eventually recreates itself and causes a short, the 30A fuse isn’t going to last much longer than a 25A would have.

I blew this fuse twice while towing the boat. I found a short in the trailer wiring where it ran through the trailer tongue. After 20 years of towing the vibration and chafing caused a short. After replacing the trailer wiring the problem was solved.

 

[Montana Ranger]

This is why I carry one of these, so at least I can quickly determine if the problem is with the trailer or the truck. Saves a lot of time.

amazon.com/gp/product/B001EOWQY4/ref=ppx_yo_dt_b_search_asin_title

 

[reidmefirst]

Old thread but I have a very related question: what exactly is "LPJ-type fuse" specified for fuse 71 from the owner manual? I'd like to order a replacement for fuse 71 because I suspect mine is either blown or missing. I'd like to have one on hand since getting the fuse box apart seems like a bit of a hassle. When I google for "LPJ type fuse" though I get some old 1920's glass tube fuses and I'm doubting that that is what is inside the fuse box...

Is it maybe like this kind? https://www.ebay.com/itm/225155276414 .

My trailer is having the same issue fwiw: power to the turn signal/brake lights works, but no power to the running lights when the headlights are turned on. I further tested the truck with some magnetic mount trailer lights that have pristine wiring, same thing. So I then tested my trailer + the magnetic mount lights with a cigarette lighter adapter that I made up: the running lights work like they're supposed to (on when the circuit is closed between black and white wires, and drawing less than 10 amps since that's the size of the fuse built into my cigarette lighter adapter). I'm guessing the fuse is blown, or a wire got cut on one of my truck's wiring harnesses ;-).

 

[reidmefirst]

Talking to myself time, but rather annoyed at the user manual.

I guess "LPJ" is the same as type G on Page 261 of the owner manual: "J Case Low Profile" ("Low Profile J-Type"?). Wish the user manual would just say "See Callout G, in Figure Whatever", or that the figure on page 261 would say "LPJ / J Case Low Profile" or something. Anyway the dimensions match up to the fuse I pulled, so I guess that's it.

Now just waiting on the mailman, and hoping that it doesn't blow again -- getting to the bottom fuse box is a pain, getting the fuse box back into its socket is even more of a pain. Seems that these are slow-blow fuses so I do wonder why it would blow when there is no apparent short on the trailer...bought my truck used though, maybe it was blown when I bought it?

 

[reidmefirst]

And, the final post.

NAPA has the fuse in question, but of course they call it something else. A "Low-Profile FMX" fuse, part number 782-2246. It is a slow-blow fuse, it fits in the socket in the fusebox, and luckily the parking/running lights are now work correctly (at least, on my magnetic lamps; I guess we'll find out later if the trailer has some fun intermittent short circuit that only reveals itself when it's actually moving). I think the 'slow blow' is important because trailer plugs may sometimes spark when you're plugging/unplugging them with the vehicle running, and a fast blow fuse would...blow, if it sparked, probably. But yadda yadda consult your Ford Dealer because who knows, maybe I'm wrong.

Anyway, hopefully the above photo helps save somebody a few minutes of fiddling with the lower fuse box, so they can just buy the spare fuse and have it on hand.

Sponsored