Hey everyone, I have a F450 that I bought a few months ago and have been having trouble with Fuse location 35 blowing. When I purchased the truck the 4x4, tow/haul, and reverse sensing system worked because I had to use it loading and unloading my boat this fall. Since then the snow fell and when I tried to put it into 4x4 I noticed it would not. I checked the passenger compartment fuse (loc. 35) and it was blown. So I figured it was an easy fix, changed fuse, and it immediately blew again, and again. So then I started checking components related to fuse 35. First i checked the tow/haul switch in the shift lever and thought it was that, so I replaced it, and it still blew fuses. Next, I unplugged the reverse sensing systems and still blew the fuse. Next, I turned my attention to the transfer case shift motor. I replaced it and still blew fuse. So at this point I am stumped. it is probably worth mentioning that when I replace the fuse initially and turn the key over, all systems work. I can switch the dash switch to 4x4 and it will shift, also the illumination light on the dash comes on. I can also toggle the tow/haul switch and the illumination light on the dash comes on as well. The reverse sensing system also works as well and the light in the switch works as well. Now and important thing to note is that it seems to hold the fuse for a minute or more with the engine off/ key on, when I start the engine, it works briefly but then the fuse blows. I am not a service tech. by any means but am very comfortable under the hood and have a fairly good understanding of electrical components and their operation. It seems to me that somewhere in the circuit that there is a short to ground or a faulty component(module) or something completely different. The fact that it takes a minute or so to blow the fuse as compared to an immediate blow when the key is cycled to power on. I would like to fix this myself as with anything I do, I like to educate myself through diagnosis/repair. The last piece of information with mentioning is that before I purchased the truck(30,000 miles ago) it had a factory reman engine installed at a ford dealer. Any help would be GREATLY appreciated. If worse comes to worse I will have to take it to a Ford dealership for service but would like to keep it in house if I could! Thanks in advance! Mitch

 

How about giving what year and trim level your truck is.

Lots of time, if a fuse blows, you have a direct short with the power circuit to ground. Have you tried chasing the wires to see if any have insulation that is missing or pinched against something metallic?

 

Thank you! Im sorry, I thought I included that information. It is a 2008 F450 king ranch. I have traced all wires that are easily accessed, and found no exposed wires. Thanks!

 

https://www.ford-trucks.com/forums/1...5-blowing.html

Tow/haul fuse blowing - Ford Powerstroke Diesel Forum

2008 f250: keeps blowing..reverse sensor-tow/hall) are on that fuse

 

Thank you for those link recommendations. I had previously located all of those threads and have taken the information in them into consideration.

 

What did you find out it was I got a 2009 f450 doing exact same thing

 

Does it do this all the time or just when you shift to 4X4?

 

All the time