Hi, I am working on my neighbors 2005 F150 king ranch, while he is away with the military, and need some help. All the trucks issues point to fuse 14, however it is not blown, nor has it ever.

No AC
No cruise control
No reverse lights
No day time running lights
ABS light is on
Brake light is on

I've read a lot of posts about all these issues being caused by fuse 14 popping, however, like I stated before, fuse 14 is fine. . . I have unplugged the pcv heater to no avail.

Also his "mechanic" friend installed his battery in backwards, and I wonder if that could have fried something or melted wires together or something along those lines

Anyone ever experience this one?

Thanks,

Chris

 

I would start with making sure you have power at that fuse. Then replace the fuse anyway (it's cheap, and you never know when you're going to get lucky), then follow the wire out of the fuse box looking for signs that it's bad and checking for power and continuity. Installing a battery in backwards can cause some strange things to happen, and can be frustrating to figure out.

 

I did ensure there was power, by checking with multi meter, then I also tried replacing the fuse twice. also out of curiosity i tried pulling the fuse with the key in the pre start position, and when it was out, nothing happened but with it in, the chiming started. This snag is driving me nuts haha

 

This sounds like it's going to be a fun one. Since the fuse isn't blowing, there's an open somewhere in the circuit. I think you're going to need to check the connectors throughout the circuit to figure out where the open is. I don't have a wiring diagram near me, so I can't advise on which one to start with (running lights, ac, reverse lights, cruise, abs.) Was there any other work done to the truck recently that might have affected this circuit?

 

The only other work that it has done, that I know of, is a transmission swap.

I was given a good piece of advice that I am going to try out tomorrow:
1- disconnect the battery
2- unplug the 3 wire bundles going into the computer.
3- inspect the female ends of the connectors for any black, or signs of singeing.
4- If any are found, then make note of the wires position in which bundle.
5- Using that info, reference the wiring diagram, to find out where that wire(s) go to
6- then shoot that system.

This should help eliminate wasting time by chasing the wrong wires... I hope

 

The DTR (digital transmission range) is on that circuit. It controls the reverse lights and the reversing aid. I would check that out considering there was transmission work done.
Checking the PCM connectors is also not a bad idea.

 

Reading up on it, the symptoms are not present for a bad DTR, as there are no shifting problems, or over heating problems, or could there be something I am missing; as the write ups do state that there could be other hidden and subtle symptoms to a malfunctioning DTR. Thanks for the heads up.

 

I was thinking more of the wiring in that area. We know the circuit is open because the fuse isn't blowing (which would indicate a short.) That could mean that a wire is broken, a connector not connected, or possibly a component of the circuit (like the dtr, cruise control, etc.) is malfunctioning (I doubt that though.) Since there was someone working on the transmission, and we know some wires to that circuit run to the transmission, it's worth checking those wires out first.

 

oh ok sorry i mis understood the first time, thank for the direction to look in. Of course it has been raining here all day and I chose not to get soaked while looking at wiring. I will get back if I find anything. Thanks again.

 

Update: I checked the wires going to the DTR and they looked fine, the DTR was rough looking so I changed it. Still no daytime running lights or reverse lights though. For the DTR, do you think it matters if the lines do not align by 1/32"?? I got them as close as I could. I hate wiring so much.