Help me identify a random wiring harness (2002 E250)

[kevman]

So I found this from a 2000 and it's pretty close.

https://www.fleet.ford.com/truckbbas...00/130_133.PDF

And this from a 2003

https://www.fleet.ford.com/truckbbas...df/122-125.pdf

I can't find it for 2002 but since 2000 and 2003 are the same I'm going to make a safe bet that 2002 was too. It does give the wire gauge and a max continuous load which is exactly what I'm looking for. Although I will have to figure out why the Orange wire isn't giving me anything at the moment.

[kevman]

So long story short, what I'm trying to figure out is whether or not I can safely use one of those leads to charge a house battery temporarily. I'm assuming that's the point and I'm probably over thinking it but a 12 gauge wire with a 25 amp continuous rating seems woefully undersized for my 235 amp hour battery.

"Temporary" as in I've got a proper isolator with real wire and a solar panel set up but I don't think I'll have time to get those in before a trip next week. I'd love to be able to use the fridge and have a small 12v power source but a cooler would probably suffice if I had to.

So, am I going to be blowing fuses like crazy or with the voltage drop on such a small wire will my actual charge current be low enough that I can get away with this for a week long trip?

[JWA]

Originally Posted by kevman

Awesome! Thanks guys!

Pardon my ignorance but what's the difference between a Battery 12V and a Battery B+? My multi-meter shows the same voltage through numerous states (engine on/off).

They are one and the same as far as I know

B+ is an old term for positive voltage, originally denoted as such because once upon a time it was important to designate whether voltages were from generated or battery power.

Originally Posted by kevman

JWA, in your manual does fuse 2.29 have a name? In mine it says not used. I wonder if instead of blowing a fuse there was never a fuse there and the original upfitter didn't even know. (Which I wouldn't put past them after seeing some of the other stuff they've done...)

That fuse location in that year is designated as Main Light Switch/Multifunction Function Switch and should contain a 25A fuse. It seems connected to the Hi/Lo headlight function inside the Multifunction Switch. If its missing is the Hi/Lo mode working properly?

[hogasm]

Is this harness readily available

[kevman]

Originally Posted by JWA

That fuse location in that year is designated as Main Light Switch/Multifunction Function Switch and should contain a 25A fuse. It seems connected to the Hi/Lo headlight function inside the Multifunction Switch. If its missing is the Hi/Lo mode working properly?

The Hi/Lo mode works fine. It's not just that it's missing, Fuse 29 is "Not Used" according to my manual. Fuse 30 is a 15A Headlamp/DRL fuse. I wonder if it's different because it's a Canadian vehicle and has day time running lights?

I did however sort out the missing power on the ignition controlled Orange wire. Fuse 15, the 5A fuse for the trailer battery charge relay was incorrectly installed in Fuse location 21 leaving fusing 15 empty. I'm guessing a previous owner did this while trying to trouble shoot their power door locks. The vehicle uses circuit breaker 43 and as a result fuse 21 is left empty. I say a previous owner because they had circled fuse 21 in the owners manual and the asterisk about fuse 21/circuit 43 has a question mark and some highlighting. In hindsight I should have known something was up based on their scribbles.

[kevman]

Originally Posted by hogasm

Is this harness readily available

It is not. That looks like a 7-pin trailer plug. Under the vehicle there is just a 4 pin plug zip-tied to the bumper. I haven't really scoped that out yet to see if it's hooked up properly.

[JWA]

Originally Posted by kevman

The Hi/Lo mode works fine. It's not just that it's missing, Fuse 29 is "Not Used" according to my manual. Fuse 30 is a 15A Headlamp/DRL fuse. I wonder if it's different because it's a Canadian vehicle and has day time running lights?

What manual are you using for all this KevMan?

My 2002 EVTM shows F2.29 (25A) as being hot at all times BUT is used only on stripped chassis, F2.10 (20A) used in the fully completed vans with any trim level. There's a page in the EVTM dedicated to Daytime Running Lights (Cell 97-1 > 97-4), no mention whether Canadian manufacture makes a difference.

That there is no fuse and is show to be "not used" makes sense if your van was originally NOT a stripped chassis.

Originally Posted by kevman

In hindsight I should have known something was up based on their scribbles.

Oh, trust me on NOT heeding those gut feelings and better judgements when it comes to trouble shooting these vehicles. Do remember "hindsight is always 20/20....." All this is a learning process, each new situation typically requiring its own solution at least in my experience.